Annual report 2005 - Eindhoven University of Technology

center for NanoMaterials 

& 

TU/e Research Priority 

Nano-engineering of Functional Materials and Devices 

Report 2005

Nano-engineering of Functional Materials and Devices / cNM 

Table of Contents 

Preface 5 

Facts and figures 7 

Scope 9 

Actual 10 

Available facilities 11 

Future 12 

CNM seminars 13 

Description of Research groups: 

Physics of nanostructures 15 

Physics of semiconductor nanostructures 21 

Molecular materials and nanosystems 29 

Theory of polymer physics 35 

Macromolecular chemistry and nanoscience 41 

Nanophotonic devices 47 

Direct write atom lithography 53 

Micron and submicron mechanics 59 

Plasma based synthesis 65 

Micro- and Nano-scale engineering 71 

2


3


Preface 

Dear colleagues and friends of cNM, 

It is now almost five years ago that the center for NanoMaterials (cNM), the Eindhoven platform for 

research and education in the field of NanoScience and Technology, has been founded. Since 

then, we have been intensively involved with many developments. On the national scale, e.g., we 

are strongly embedded within the Dutch NanoTechnology initiative, NanoNed. New opportunities 

are provided by the new open innovation centers, The Holst Center and the Center for Molecular 

Medicine, at the Philips High-Tech campus at Eindhoven. Moreover, by the end of the year 2005, 

a decision for the foundation of five new Centers of Excellence aiming at guiding new, coherent 

research programs at the three Dutch Universities of Technology (Eindhoven, Delft and Twente) 

has been made. The Center of Excellence on Nanosensing and bio-nanoapplications will be one of 

them. Also allied to this the 3TU-initiative, extending our master program on NanoScience & 

Technology with the Radboud University at Eindhoven to a national Masters with input from the 

three Universities of Technology and their partner institutes is being planned. 

Within the university, the research priority “Nano-engineering of Functional Materials and 

Devices” has become one of the ten main research priorities, as defined in 2004. Since then, 

activities of cNM and the research priority have merged. As the most recent strategic 

interdisciplinary initiative, within 2005 a new group on Biosensors for Molecular Diagnostics has 

been founded, with its roots in the Department of Applied Physics, but certainlty aiming at (and 

already successful in) nucleating new cross-disciplinary research over different departments. 

The present report provides an overview over (research) activities and profiles of groups 

participating in 2005. As you will recognize, we can look back to a rich series of interdisciplinary 

cNM seminars, as well as a very successful Research Day. Around that day, we received highly 

appreciated feedback on our performance by two members of our international advisory board, 

Prof. Kirschner (Halle) and Prof. Fuchs (Münster). This year, among the main activities will be 

the “SuperTU/esday” on Nanotechnology, an event celebrating the fiftieth anniversary of the 

university, and aiming to make a wide audience, ranging from children at primary schools to 

adults, enthusiastic for science and technology. 

Taking the freedom to close this preface by citing the last words of Prof. Kirschner’s evaluation 

report, written at the occasion of his visit to our center: “I congratulate the members of the cNM 

for their outstanding achievements, the research-oriented atmosphere, their attention to future 

developments, and their excellent organization. The cNM is on a very good way!” 

On behalf of the cNM members, 

Bert Koopmans 

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5


Facts and Figures 

Organization 

With the foundation of the Center for NanoMaterials (cNM), October 12, 2001, the TU/e strives to 

give a strong impulse to the fundamental and technological research of materials and devices with 

critical dimensions in the (sub)nanometer region. The center should foster a further integration 

of the existing excellent research activities on nanotechnology by facilitating multidisciplinary 

research, promoting exchange of expertise and the expansion of the available infrastructure. 

The Research Priority “Nano-engineering of Functional Materials and Devices” is one of the ten 

research themes defined in 2004 after a self-assessment of the Eindhoven University of 

Technology. The Research Priorities, facilitate a well recognizable research profile of the 

university. 

Scope 

Bottom-up nano-engineering of functional materials and structures and top-down reduction of 

devices and micro-systems into the nano-range. 

Participating departments 

Applied Physics (TN) 

Chemical Engineering and Chemistry (ST) 

Mechanical Engineering (W) 

Electrical Engineering (E) 

Biomedical Engineering (BMT) 

Coordination and chairs 

cNM: chair: W.J.M. de Jonge, Applied Physics 

coordinator: B. Koopmans, Applied Physics 

Research Priority: 

coordinator: W.J.M. de Jonge, Applied Physics 

Participating full chairs 

B. Koopmans / H.J.M. Swagten / W.J.M. de Jonge TN 

P.M. Koenraad / H.W.M. Salemink TN 

R.A.J. Janssen ST / TN 

M.A.J. Michels TN 

U.S. Schubert ST 

M.W.J. Prins TN 

M.K. Smit E 

H.C.M. Beijerinck / K.A.H. van Leeuwen TN 

M.G.D. Geers W 

M.C.M. van de Sanden / D.C. Schram TN 

A.H. Dietzel W 

Participation in (top)institutes and research schools 

DPI, PTN, EPL, Cobra, EM, NIMR and cNM. 

6


Total research fte involved 

Physics of nanostructures 13.1 

Physics of semiconductor nanostructures 12.3 

Molecular materials and nanosystems 10.0 

Theory of Polymer Physics 5.1 

Macromolecular chemistry and nanoscience 10.1 

Nanophotonic devices 3.6 

Direct write atom lithography 2.6 

Micron and Submicron mechanics 3.8 

Plasma based synthesis 6.0 

Total research fte involved in profile Nano-engineering: 66.6 

(amounts to approx. 80 fte in total) 

International Advisory Board of the cNM 

Prof.dr. J. Kirschner - Max-Planck-Institut fuer Mikrostrukturphysik, Halle 

Prof.dr. J. Feldmann - Ludwig-Maximilians-Universität, München 

Prof.dr. H. Fuchs - Westfalische Wilhelms-Universität, Münster 

Prof.dr. J.K. Gimzewski - University of California 

Prof.dr. H.G. Craighead - Cornell University 

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Scope 

Worldwide efforts and investments are creating the foundations for realistic contributions from 

nanotechnology, in such diverse fields as electronics, photonics, organic devices, drug delivery, 

molecular screening and biotechnology. 

The center for NanoMaterials and the profile “Nano-engineering: functional materials and devices” 

at the TU/e deliver a strong impulse for science and technology of materials, devices and their 

design, with critical dimensions in the nanometer range. This profile is driven by the notion that 

manipulation at the nanometer scale, bottom-up design of molecular structures of increasing 

complexity and functionality, and an integration of physics, chemistry and life sciences, will be 

key elements in science and technology for the forthcoming decades, e.g. see RAND report (1). 

Over the past years, a large number of activities related to nanoscience and nanotechnology have 

already been initiated at the TU/e, as outlined in memo (2). With the presence of three top 

research schools and technological top institutes at TU/e: the Dutch Polymer Institute (DPI) / 

Polymers PTN, COBRA / Photonics and NRSC-Catalysis / NIOK, an enormous potential for 

leading contributions in this explosively growing field of nano-research is available. The new 

department for Biomedical Engineering has become a strong catalytic center for life sciences at 

TU/e. A coordination of multidisciplinary activities, mutual sharing of expertise and enabling 

technologies, and the gathering of renowned scientists will facilitate the optimal boundary 

conditions and atmosphere for forefront scientific contributions, education, and training of young 

researchers at a high level. 

Combining the existing strength in the contributing departments at the TU/e allows to acquire an 

internationally recognized position in: 

• Exploitation of the knowledge from nanoscience and nanotechnology and its utilization in 

addressing and manipulation of individual objects (molecules) to design and construct 

more complex, functional entities / devices (bottom-up approach). 

• Advancing (top-down) technologies - with proven capabilities- into the regime with critical 

dimensions in nanometers. 

• Development of engineered functional materials, via modeling and nanotechnologic 

synthesis, based on the (self)assembly of atomic/molecular/organic building blocks. 

The approach, as also summarized in the mission of the “center for NanoMaterials” (cNM): 

• Stimulation of research on nanotechnology that is relevant for our three top research 

schools/institutes, and exploit synergy. 

• Investments in two directions: first, acquiring specific skills and persons to work in this 

profile at various positions; second, upgrading of our nanoscale toolset and equipment to 

enable cross-fertilization in an effective way. 

• A strong emphasis on the education and training of young researchers in the multidisciplinary 

environment (offering a masters degree in nanotechnology). 

We will exploit in a symbiotic way our strong and extended network with related universities (TU 

Delft, University Twente, KU Nijmegen), with national industrial partners (Philips, ASML, DSM, 

Océ) and internationally renowned centers for fundamental research. As such it will stimulate the 

participation in existing networks and the foundation of new networks. 

1 RAND report 2001 for National Intelligence Council US, The global technology revolution: 

bio/nano/materials trends and their synergies with information technology by 2015. (Philip 

S. Anton, Richard Silberglitt, James Schneider). 

2 Internal TU/e memo “Nano-Science and Technology @ TU/e”, January 2001. 

8


Actual 

The center for nanoMaterials and the research-theme Nano-engineering are based on the fields of 

nanoscience and nanotechnology and have a particular focus on the topics that offer 

“engineering” aspects on a nanometer-scale. It concentrates on materials and device aspects with 

an ultimate aim at well-designed applications. For these directions we master the complete 

knowledge chain from concepts, via materials to devices/prototypes. This focus area combines the 

recognized expertise at the TU/e in the research fields of: 

• polymer-physics and theory, 

• (magneto)-engineering and spintronics, 

• (macro)molecular chemistry and self-assembly of materials, 

• (semiconductor) nanostructures, 

• nanophotonic devices 

• atom-lithography 

• mechanics 

The nano-scale aspects are visible in the theory, in the materials-synthesis, in materials-analysis 

and in the fabrication technology. The chain in nanotechnology encompasses bottom-up as well 

as top-down approaches. Fields with a clear view on applications are emphasized: in this sense we 

create a research and training environment that positions the TU/e uniquely in several ways, both 

nationally and internationally: 

• it complements to general nanoscience efforts, 

• it selects particular nanotechnology directions, 

• it reinforces overlapping interests with industrial efforts in which we already cooperate – 

and will deliver new insights in these cooperations, 

• it will be attractive to students with an interest in choosing careers in applied 

nanotechnology, offering a multidisciplinary activity, 

• it positions this focus area in a concentrated portfolio in view of future research and 

funding opportunities. 

The profile as outlined above, with the emphasis on nano-engineering of functional materials and 

device structures, is complementary with the related nano-programs at the TUD and UT (see 

discussion between the 3 TUs and in NanoNed) and strongly interconnects with the nanoscience 

research fields of the KUN, as also can be monitored from the current and forthcoming national 

programs orchestrated in NanoNed and NanoImpuls. This explains the current formation of a 

combined TU/e-KUN Master course in the field of nano-engineering. 

In realization of the multidisciplinary character of nanotechnology and recognizing the widely 

diverse impact of this field, the faculties TN ST and BMT have formed in 2001 a Center of 

NanoMaterials (CNM) with the intention to reinforce their research and education activities 

related to nanotechnology; see memo (3). This effort has resulted in increased mutual activity, 

notably between the departments TN and ST, in a common seminar series and in joint proposals 

in new opportunities for funding of nanotechnology. 

3 Memo on TU/e Center of Expertise, “center for NanoMaterials cNM ”, Platform for research 

and education, April 27, 2001and revision October 3, 2001. 

9


Available facilities 

The available facilities for this profile range from design/theory, materials synthesis/fabrication, 

and materials analysis to functionals prototypes (first-of-a-kind) and include: 

• Since early 2003 a newly constructed technology building (“Spectrum”) with technical 

laboratories, low-vibration laboratories and clean-room facilities is realized. 

• Materials synthesis and thin film growth: self-assembly and (epitaxial) growth of a wide 

range of materials (oxides, organic, metals, semiconductors). 

• Wide range of state-of-the-art, ultra-fast laser spectroscopy-techniques over large 

wavelength range (UV to NIR). 

• Suite of scanning probe tools for nanometer scale analysis (also automated units): 

tunneling, force and friction microscopies under a range of relevant conditions: ambient 

atmosphere, with optical access, ultra-high vacuum, low temperature; nano-indenters. 

These tools are used for analysis, lithography and manipulation. 

• Inkjet printing facility for the defined delivery of polymer droplets. 

• Suite of electron and ion beam tools for fabrication and analysis: electron beam 

lithography, high-resolution scanning and transmission electron microscopes, Cryo/TEM 

(in 2004). 

• Ion-based plasma etching, plasma deposition and sputtering machines. 

• Laser based lithography. 

• Theory based on physical first principles: electronic structure and micromechanics; multi 

variance finite element theory. 

10


Future 

Based on the available expertise within the constituting departments, it is expected that the 

research theme Nano-engineering adds value and provides new, internationally interesting 

pathways in the design and fabrication of composite materials (inorganic and organic), in the use 

of nanotechnology to demonstrate new concepts and devices (polymeric, photonic, magnetic) and 

(industrially) interesting utilizations (catalytic activity, optical emitters and optical sensors, 

photon-convertors, nanoscale fluidic devices, molecular recognition and sorting). A large fraction 

of the new research themes under Nano-engineering is formulated in the programs NanoImpuls 

(approved December 2002 and currently executed via STW) and NanoNed (under evaluation in 

Bsik –ICES/KIS-3). Similar to the international activities in nanotechnology, a major thrust into 

the field of life-science technology is expected to develop. The unique opportunity for Nanoengineering 

at TU/e is in the utilization of science and technology for devices/sensors with 

realistic (industrial) applications, given our contacts with the technological base in the 

Netherlands. 

The following strategically chosen research areas will be covered: 

1. Materials design, self assembly and self organization, 

2. Functional materials and nanoscopic devices, 

3. Integrated catalysis and nanochemistry, 

4. Bionanotechnology and medical applications, 

5. Long-term research with generic applications. 

The research and education activities are embedded in the participating schools and institutes 

(DPI, PTN, EPL, Cobra, cNM) and relates to the portfolio profile Polymers. 

11

Nano-engineering / cNM Physics of Nanostructures 

The cNM seminars 2005 

Prof. Andreas Dietzel (Dept. Mechanical Engineering) 

"Ion Projection Direct Structuring for Nano-Patterning of Magnetic Media" 

April 13, 2005 

Alfons van Blaaderen (Debye Institute, Utrecht University) 

"Colloids under External Control" 

April 27, 2005 

Dirk Burdinski (Philips Research, Eindhoven) 

"Microcontact Wave Printing for Electronic Devices" 

Wednesday, May 25, 2005 

Sergei Magonov (Veeco Instruments, Santa Barbara, CA) 

"Atomic Force Microscopy in its Application to Soft Condensed Matter” 

Wednesday, June 8, 2005 

Hans-Jürgen Butt (Max-Planck-Institute for Polymer Research, Mainz, Germany) 

"Atomic force microscopy: A routine tool or emerging technique?" 


Harald Fuchs (Physikalisches Institut, Universitaet Muenster) 

“Self organized organic systems and their characterization by dynamic scanning probes" 


Henning Sirringhaus (Cavendish Laboratory, University of Cambridge - UK) 

"Electron and hole transport at polymer heterointerfaces" 

Wednesday, September 21, 2005 

Ulrich Koert (Philipps-Universität Marburg) 

"Synthetic ion channels and conformational switches" 

Wednesday, October 26, 2005 

Miquel Salmeron (Lawrence Berkeley Natl. Laboratory, Univ. California, Berkeley) 

"Nanometer scale mechanical and electronic properties of molecular films" 

Monday, November 7, 2005 

The cNM Research day 2005 

June 6, Auditorium, TU/e 

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The cNM Research day 2005 

June 6, Auditorium, TU/e 

Guest Lecture: Jürgen Kirschner (MPI für Microstrukturphysik, Halle) 

"Physics and technology of magnetic nanostructures" 

Michael Meier (Macrmolecular Chemistry and Nanoscience) 

“Tailor-made unimolecular micelles for drug delivery, sensor applications or catalysis” 

Erik Bogaart (Semiconductor Physics) 

“Carrier relaxation in quantum dots” 

Vici-Lecture: Ulrich Schubert (Macrmolecular Chemistry and Nanoscience) 

“(Macro)molecular engineering on the nanoscale” 

Francesco Dalla Longa (Physics of Nanostructures) 

“Femtosecond dynamics in magnetic nanostructures” 

Chris Meisel (Polymer Physics) 

“Polarons and charge transport in polymers” 

Ton van Leeuwen (Atom Physics and Quantum Technology) 

“Atom lithography” 

Rik van Laarhoven (Molecular Materials and Nanosystems) 

“Electron and hole vibrational coupling in oligoacene single crystals” 

13


Physics of Nanostructures B. Koopmans / H.J.M. Swagten / W.J.M. de Jonge 

Research in the group aims at the exploration and exploitation of novel physical phenomena at the 

nanometer scale by engineering the (magnetic) properties and structure of nanosystems. The 

program is inspired by the challenges of nanoscience and nanotechnology. At present, the main 

emphasis is on processes and systems that are relevant for the future development of (magnetic) 

data storage and spinelectronics. While this approach is strongly curiosity driven, it is the aim to 

select in particular those issues that potentially have a high technological impact. 

Research themes 

1. Nanomagnetism. Deposition of and engineering of layered and nanostructured systems. 

In-situ and ex-situ characterization of structural and magnetic properties. Implementation 

and development of novel SPM methods for analysis and manipulation at nanometer to 

atomic scale. 

2. Spintronics. Tailoring spin-polarized transport in ferromagnetic and hybrid 

nanostructures. Specific emphasis on magnetic tunnel-junctions, spin-injection / 

manipulation in(to) semiconductors, and molecular spintronics. 

3. Ultrafast spin dynamics. Investigation of ultimate limits of spin dynamics in ferromagnetic 

nanostructures. Development of novel concepts for high-data rate recording. Development 

of near-field femtosecond magneto-optical microscopy. 

4. Molecular systems. Engineering of single-molecule and self-assembled molecular systems, 

including UHV deposition of molecular films, molecular spintronic devices, scanning 

probe manipulation and biosensors. 

Keywords 

Spintronics, magnetism, magnetic nanostructures, spin polarized transport, magnetic 

tunneljunctions, ultrafast spindynamics, scanning probe microscopy, molecular electronics, 

molecular manipulation, biosensors 

Staff involved 

Total Research 

Senior staff 4.2 2.1 

PhD 10.0 8.0 

Post doc 3.0 3.0 

Total (fte) 13.1 

Key publications 

A.T. Filip, P. LeClair, C.J.P. Smits, J.T. Kohlhepp, H.J.M. Swagten, B. Koopmans and W.J.M. de 

Jonge, Spin injection device based on EuS magnetic tunnel barriers, Appl. Phys. Lett. 81, 1815 

(2002) 

O. Kurnosikov, J.T. Kohlhepp and W.J.M. de Jonge, Can surface embedded atoms be moved with 

an STM tip? Europhys. Lett., 64, 73 (2003) 

14


C.H. Kant, J.T. Kohlhepp, H.J.M. Swagten, and W.J.M. de Jonge, Intrinsic thermal robustness of 

tunneling spin polarization in Al/Al2O3/Co junctions, Appl. Phys. Lett. 84, 1141 (2004) 

H. Wieldraaijer, W.J.M. de Jonge, and J.T. Kohlhepp, Monolayer resolved oscillating hyperfine 

fields in epitaxial fct-Co(001) films, Phys. Rev. Lett. 93, 177205 - 177208 (2004) 

B. Koopmans, J.J.M. Ruigrok, F. Dalla Longa, and W.J.M. de Jonge, Unifying ultrafast 

magnetization dynamics, Phys. Rev. Lett. 95, 267207 (2005) 

Research highlight 

The understanding of the influence of nanometer or even 

atomic scale roughness on the magnetic and transport 

properties of magnetic heterostructures is a crucial step for 

a controlled design of modern nanostructured spintronic 

devices with well defined functionalities. One of the key 

components in GMR devices, magnetic tunnel junctions or 

other spintronic devices in general, are i.e. very often 

antiferromagnetic (AFM) layers which are exchange- 

120 X 120 nm 

coupled to ferromagnetic (FM) layers. Here the function of 

the AFM layer is to pin the magnetization direction of the 

adjacent FM layer to a certain direction. The AFM/FM 

30 

25 

interface quality on an atomic scale plays here a crucial 20 

role for the determination of the magnetic switching 15 

behavior. We have demonstrated this with our recently 

developed single-crystalline Co/Mn(001) FM/AFM model 

system. The growth of Co(001) on a single crystal 

Cu(001) is characterized by the expansion and coalescence 

10 

5 

40 

of islands of single-atom height with a Co-monolayer 

(ML) periodicity (layer-by-layer growth), which 

30 

consequently forms the template for the Mn growth (see 

STM pictures). This opens up the possibility to investigate 

20 

the influence of a well-defined atomic-scale roughness at 

the AFM/FM interface on the exchange interaction in 

10 

detail. We have shown that both the magnetization loop 

8 9 10 11 12 13 14 

shift (HE) and the coercive force (HC) oscillate with a Co- 

ML periodicity showing maxima (minima) for half-filled 

Co Layer Thickness (ML) 

(filled) Co template layer surfaces, respectively. The significance of these results lie in the 

unambiguous demonstration that atomic scale interface roughness can dramatically influence 

exchange interactions as demonstrated by our experiments which could only be achieved by the 

exceptional level of control that can be achieved in single-crystal heterostructures. 

2 

Senior scientific staff 

Prof.dr. B. Koopmans 

Bert Koopmans is a full professor, and group leader since 2003. His research interests encompass 

spintronics (including hybrid semiconductor and molecular devices – the latter being 

implemented within his NWO-Vici grant 2004), nanomagnetism and ultrafast spin dynamics. At 

present, he is coordinator of the center for NanoMaterials (cNM) and captain of the flagship 

Nanospintronics, one of programs within the Dutch NanoTechnology Initiative 

NanoNed/NanoImpuls. He is in the general representative of TU/e within NanoNed. 

15 

|H E | (kA/m) 

H C (kA/m) 

10.5 ML Co(001) 11.0 ML Co(001)


Prof.Dr.Ir. H.J.M. Swagten 

Henk Swagten is associate professor in the group Physics of Nanostructures. His current 

activities are focusing on new phenomena in the area of spintronics, such as spin-polarized 

tunnelling across nano-oxide layers, spin filtering and spin injection in nano-layered magnetic 

devices, and the imaging of spin phenomena on a nanometer scale using scanning probe 

techniques. These subjects are fully incorporated in the recently granted NWO-VICI program on 

spintronics. 

Prof.dr.ir. W.J.M. de Jonge 

Wim de Jonge is a full professor, group leader until 2003, and dean of the department of applied 

physics. Over the past decades his research interest has been in diluted magnetic semiconductors, 

high Tc superconductors, as well as magnetic thin films, magnetic multilayers, artificial 

nanostructures and their applications. In 2000 he received the KNAW Holst prize for his work, 

together with Philips Research, on giant-magnetoresistance and tunnel magnetoresistance. 

Dr. J.T. Kohlhepp 

Jürgen Kohlhepp is an assistant professor. He has more than fifteen years of experience with the 

preparation (Molecular Beam Epitaxy, UHV-Sputter Deposition) and the characterization of the 

structural, the magnetic and the electronic properties of (ultra)thin films, multilayered systems, 

surfaces and interfaces, and magnetic devices. 

Dr. O. Kurnosikov 

Oleg Kurnosikov is a senior researcher, in charge of several projects related to applications and 

development of scanning probe microscopies. Activities encompass low-temperature STM 

(including atomic manipulation), hot-electron microscopy, MFM and near-field magneto-optics. 

Selected publications 2001-2005 

2001 

P. LeClair, J.T. Kohlhepp, H.J.M. Swagten, W.J.M. de Jonge, Interfacial density of states in magnetic tunnel 

junctions, Phys. Rev. Lett. 86, 1066 (2001) 

H. Kepa, J. Kutner-Pielaszek, J. Blinowski, A. Tardowski, C.F. Majkrzak, T. Story, P. Kacman, R.R. Galazka, 

K. Ha, H.J.M. Swagten, W.J.M. de Jonge, A. Yu. Sipatov, V. Volobuev, T.M. Giebultowicz, Antiferromagnetic 

interlayer coupling in ferromagnetic semiconductor EuS/PbS(001) superlattices, Europhysics Lett. 56, 54 

(2001) 

D. Alders, R. Coehoorn, W.J.M. de Jonge, Single-ion anisotropy of localized-electron compounds, Phys. Rev. 

B 63, 054407 (2001) 

P.J. van Hall, Ultrafast processes in Ag and Au: A Monte Carlo study, Phys. Rev. B 63, 104301 (2001) 

O. Kurnosikov, F.C. de Nooij, P. LeClair, J.T. Kohlhepp, B. Koopmans, H.J.M. Swagten, W.J.M. de Jonge, 

STM-induced reversible switching of local current transport in thin Al2O3 films, Phys. Rev. B 64, 153407 

(2001) 

W. Oepts, M.F. Gillies, R. Coehoorn, R. van de Veerdonk, W.J.M. de Jonge, Asymmetric bias voltage 

dependence of the magnetoresistance of Co/Al2O3/Co magnetic tunnel junctions: variation with the barrier 

oxidation time, J. Appl. Phys. 89, 8038 (2001) 

K. Knechten, P. LeClair, J.T. Kohlhepp, H.J.M. Swagten, B. Koopmans, W.J.M. de Jonge, In situ timeresolved 

optical studies of Al oxidation for magnetic tunnel junctions, J. Appl. Phys. 90,1675 (2001) 

P. LeClair, B. Hoex, H. Wieldraaijer, J.T. Kohlhepp, H.J.M. Swagten, W.J.M. de Jonge, Sign reversal of spin 

polarization in Co/Ru/Al2O3/Co magnetic tunnel junctions, Phys. Rev. B Rapid Communications 64, 

100406 (2001) 

B. Koopmans, M. van Kampen, J.T. Kohlhepp, W.J.M. de Jonge, Femtosecond magneto-optics: Spin 

16


dynamics in ferromagnetic layered systems, Material Science Forum Vols. 373-376, 69 (2001) 

W. Oepts – Magnetic tunnel junction device having an intermediate layer, Patent No.: US 6,295,225 B1, 

Date of Patent: Sep. 25, 2001. 

2002 

P. LeClair, J.T. Kohlhepp, C.H. van de Vin, H. Wieldraaijer, H.J.M. Swagten, W.J.M. de Jonge, H. Davis, J.M. 

MacLaren, J.S. Moodera and R. Jansen, Band structure and density of states effects in Co-based magnetic 

tunnel junctions, Phys. Rev. Lett. 88, 107201 (2002) 

M. van Kampen, C. Josza, J.T. Kohlhepp, P. LeClair, W.J.M. de Jonge, and B. Koopmans, All-optical probe of 

coherent spin waves, Phys.Rev. Lett. 88, 227201 (2002) 

P. LeClair, J.K. Ha, H.J.M. Swagten, C.H. van de Vin, J.T. Kohlhepp, and W.J.M. de Jonge, Large 

magnetoresistance using hybrid spin filter devices, Appl. Phys.Lett. 80, 625 (2002) 

A.T. Filip, P. LeClair, C.J.P. Smits, J.T. Kohlhepp, H.J.M. Swagten, B. Koopmans and W.J.M. de Jonge, Spin 

injection device based on EuS magnetic tunnel barriers, Appl. Phys. Lett. 81, 1815 (2002) 

O. Kurnosikov, J.E.A. de Jong, H.J.M. Swagten, and W.J.M. de Jonge, Direct observation of local hot electron 

transport through an Al2O3 tunnel junctions, Appl. Phys. Lett. 80, 1076 (2002) 

A.J.M. van Erven, T.H. Kim, M. Muenzenberg and J.S. Moodera, Highly crystallized as-grown smooth and 

superconducting MgB2 films by molecular-beam epitaxy, Appl. Phys. Lett. 81, 25 (2002) 

R.W.E. van de Kruijs, M.Th. Rekveldt, H. Fredrikze, J.T. Kohlhepp, J.K. Ha, and W.J.M. de Jonge, Magnetic 

interlayer exchange coupling in epitaxial Fe/Si/Fe(100) studied by polarized neutron reflectiometry, Phys. 

Rev. B 65, 064440 (2002) 

M.V. Tiba, O. Kurnosikov, C.F.J. Flipse, B. Koopmans, H.J.M. Swagten, J.T. Kohlhepp, and W.J.M. de Jonge, 

Ordering of organic molecules on passivated reactive substrates: PTCDA on O p(2x2) – Ni(111), Surf. Sci. 

498, 161 (2002) 

C.H. Kant, O. Kurnosikov, A.T. Filip, P. LeClair, H.J.M. Swagten and W.J.M. de Jonge, Origin of spin 

polarization decay in point contact Andreev reflection, Phys.Rev.B. 66, 212403 (2002) 

J.T. Kohlhepp, P. LeClair, H.J.M. Swagten, and W.J.M. de Jonge, Interfacial sensitivity and zero-bias 

anomalies in magnetic tunnel junctions, Phys. Stat. Sol. 189, 261 (2002) Editor’s Choice 

2003 

O. Kurnosikov, J.T. Kohlhepp and W.J.M. de Jonge, Can surface embedded atoms be moved with an STM 

tip? Europhysics Letters, 64, 73 – 83 (2003) 

P.H.P. Koller, F.W.M. Vanhelmont, H. Boeve, R. Coehoorn and W.J.M. de Jonge, The oxidation process of 

AIOx-based magnetic tunnel junctions studied by photoconductance, Journal of Applied Physics 93, 8549 

(2003) 

H. Wieldraaijer, J.T. Kohlhepp, P. LeClair, K.Ha and W.J.M. de Jonge, Growth of epitaxial bcc Co(001) 

electrocodes for magnetoresistive devices, Physical Review B, vol. 67 (22), 224430 (2003) 

B. Koopmans, M. van Kampen and W.J.M. de Jonge, Experimental access to femtosecond spin dynamics, J. 

Phys.: Condens. Matter 15, S723-S736 (2003) 

G. Tanasa, O. Kurnosikov, C.F.J. Flipse, J.G. Buijnsters and W.J.P. van Enckevort, Diamond deposition on 

modified silicon substrates: Making diamond atomic force microscopy tips for nanofriction experiments, 

Journal of Applied Physics, 94, 1699 – 1704 (2003) 

F. Walz, V.A.M. Brabers, J.H.V.J. Brabers, and H. Kronmueller, Stress-induced relaxation mechanisms in 

single-crystalline titanomagnetic, J.Phys.: Condens.Matter 15, 7029 (2003) 

G. Zoriniants, D. Englund, O. Kurnosikov, C.F.J. Flipse, E. Rido, H. Brune, W.J.M. de Jonge and B. 

17


Koopmans, Development of a near-field magneto-optical microscopy for studying ultrafast magnetization 

dynamics, AIP conference proceeding 696, 204 (2003) 

M.V. Tiba, O. Kurnosikov, C.F.J. Flipse, H.J.M. Swagten, J.T. Kohlhepp, R.A.J. Janssen, P.M. Koenraad, 

W.J.M. de Jonge and B. Koopmans, Growth of organic molecules on ferromagnetic metallic substrates – a 

combined STM/AFM study, AIP conference proceeding 696, 521 (2003) 

M. Chernyshova, L. Kowalczyk, A. Szczerbakow, T. Story, C.J.P. Smits, H.J.M. Swagten, C.H.W. Swuste, J.K. 

Ha, W.J.M. de Jonge, A.Y. Sipatov and V.V. Volobuev, Magnetization of EuS-PbS Multilayers with 

Antiferromagnetic Interlayer Coupling, J. Supercond. 16, 213 (2003) 

C.H. Kant, O. Kurnosikov, A.T. Filip, H.J.M. Swagten and W.J.M. de Jonge, Interface spin-flip scattering 

model for point contact Andreev reflection, Journal of Applied Physics, 93, 7528 - 7530 (2003). 

C.H. Kant, J.T. Kohlhepp, H.J.M. Swagten, W.J.M. de Jonge, Intrinsic thermal robustness of tunneling spin 

polarization in Al/Al2O3/Co junctions, Applied Physics Letters 84, 1141 (2004) 

2004 

H. Wieldraaijer, W.J.M. de Jonge, J.T. Kohlhepp, Monolayer resolved oscillating hyperfine fields in epitaxial 

fct-Co(001) films, Phys. Rev. Lett. 93, 177205 (2004). 

G. Ju, J. Hohlfeld, B. Bergman, R.J.M. van de Veerdonk, O.N. Mryasov, J.-Y. Kim, X. Wu, D. Weller, B. 

Koopmans, Ultrafast generation of ferromagnetic order via laser-induced phase transformation in FeRh 

thin films, Phys. Rev. Lett. 93, 197403 (2004). 

C.H. Kant, A.T. Filip, H.J.M. Swagten, W.J.M. de Jonge, Comment on “Direct measurement of the spin 

polarization of the magnetic semiconductor (Ga,Mn)As”, Phys. Rev. Lett. 93, 169703 (2004) 

P. H. P. Koller, H. J. M. Swagten, and W. J. M. de Jonge, H. Boeve, R. Coehoorn, Direct observation of the 

barrier asymmetry in magnetic tunnel junctions, Applied Physics Letters 84, 4929 (2004). 

C.H. Kant, J.T. Kohlhepp, H.J.M. Swagten, B. Koopmans, W.J.M. de Jonge, Role of the barrier in spindependent 

tunneling addressed with superconductor spectroscopy, Phys. Rev. B 69, 172408 (2004). 

C. Jozsa, J.H.H. Rietjens, M. van Kampen, E. Smalbrugge, M.K. Smit, W.J.M. de Jonge, B. Koopmans, 

Retrieving pulse profiles from pump-probe measurements on magnetization dynamics, J. Appl. Phys. 95, 

7447 (2004) 

J.T. Kohlhepp, W.J.M. de Jonge, Influence of the FM/AFM interface morphology on the exchange coupling 

in epitaxial Co(001)/fct-Mn(001), J. Appl. Phys. 95, 6840 (2004) 

C.J.P. Smits, S.C.A. van Driel, M. van Kampen, W.J.M. de Jonge, B. Koopmans, G. Karczewski, Exciton 

enhancement of spin relaxation in diluted magnetic semiconductor quantum wells, Physical Review B 70, 

115307 (2004) 

O. Kurnosikov, J.T. Kohlhepp, W.J.M. de Jonge, STM-tip induced displacement of Co atoms embedded in a 

Cu(001) surface, Surf. Science 566, 175 - 180 (2004) 

K. Knechten, B.J. Kniknie, R. Engeln, H.J.M. Swagten, B. Koopmans, M.C.M. van de Sanden, W.J.M. de 

Jonge, TALIF on ozone in a DC plasma for oxidation of aluminum, J. Vac. Sc. Tech. A 22, 11 - 14 (2004) 

2005 

B. Koopmans, J.J.M. Ruigrok, F. Dalla Longa, and W.J.M. de Jonge, Unifying ultrafast magnetization 

dynamics, Phys. Rev. Lett. 95, 267207 (2005) 

J.H.H. Rietjens, C. Józsa, H. Boeve, W.J.M. de Jonge, and B. Koopmans, Effect of stray field on local spin 

modes in exchange-biased magnetic tunnel junction elements, Appl. Phys. Lett. 87, 172508 - 3 (2005) 

P.H.P. Koller, H.J.M. Swagten, W.J.M. de Jonge, and R. Coehoorn, Change of the barrier potential shape in 

magnetic tunnel junctions due to an anneal treatment, Appl. Phys. Lett. 86, 102508 - 3 (2005) 

18


W.P.E.M. Op 't Root, H.J.M. Swagten, F.J. Jedema, and A.E.T. Kuiper, Magnetic read-only memory with 

removable medium, Appl. Phys. Lett. 87, 203501 - 3 (2005) 

H. Wieldraaijer, W.J.M. de Jonge, and J.T. Kohlhepp, Electrical-field gradients in thin face-centeredtetragonal 

Co films observed by nuclear magnetic resonance, Phys. Rev. B 72, 155409 - 10 (2005) 

J.T. Kohlhepp, O. Kurnosikov, and W.J.M. de Jonge, Oscillatory biquadratic antiferromagnet/ferromagnet 

interface exchange coupling, J. Magn. Magn. Mater. 286, 220 - 224 (2005) 

M. van Kampen, I. Sorroka, R. Brucas, B. Hjorvarsson, R. Wieser, K.D. Usadel, M. Hansson, O. Kazakova, 

H. Zabel, J. Grabis, C. Józsa, and B. Koopmans, On the realisation of artificial XY spin-chains, J. Phys. 

Cond. Mat. 17, 27 - 33 (2005) 

H. Wieldraaijer, W.J.M. de Jonge, and J.T. Kohlhepp, 59Co NMR observation of monolayer resolved 

hyperfine fields in ultrathin epitaxial fct-Co(001) films, J. Magn. Magn. Mater. 286, 390 - 393 (2005) 

P.V. Paluskar, C.H. Kant, J.T. Kohlhepp, A.T. Filip, H.J.M. Swagten, B. Koopmans, and W.J.M. de Jonge, Mn 

diffusion and the thermal stability of tunneling spin polarization, J. Appl. Phys. 97, 925 (2005) 

A.T. Filip, J.J.H.M. Schoonus, H.J.M. Swagten, B. Koopmans, W.J.M. de Jonge, F. Karouta, E.J. van Geluk, 

W. van Roy, and J, Towards All Electrical Spin Injection and Detection in GaAs in a Lateral Geometry, J. 

Supercond. (2005) 

19

Nano-engineering / cNM Physics of Semiconductor Nanostructures 

Physics of Semiconductor Nanostructures 

P.M. Koenraad / J.H. Wolter / H.W.M. Salemink 

The central research issue is the study of self-assembled growth and investigation of structural, 

electrical and optical properties of semiconductor nanostructures. The structures are engineered 

and controlled on a nano-meter scale. The scope of the activity ranges from physics to 

engineering, from materials to devices. 


1. Quantum confinement structures. Controlled growth of quantum confined semiconductor 

III/V semiconductor structures by molecular beam epitaxy (MBE), chemical beam epitaxy 

(CBE) and metal-organic vapor phase epitaxy (MOVPE), in particular formation of 

quantum wires and quantum dots on naturally corrugated and patterned high-and lowindex 

substrates to the InP based material system. 

2. Nanoprobing techniques. Nano-probe assembly and analysis of structural and optical 

properties via laser and scanning probe techniques (structures mentioned in 1). Crosssectional 

Scanning Tunneling Microscopy (X-STM) under UHV conditions, Atomic Force 

Microscopy (AFM) at ambient conditions and STM induced luminescence (STL) in the 

temperature range from 4K to 300K. 

3. Ultrafast laser techniques. Optical investigation of 0D, 1D and 2D quantum structures, 

using a variety of advanced laser techniques from visible to near IR, including ultrafast 

laser spectroscopy. Femtosecond carrier dynamics and multi-exciton dynamics in 

quantum dot structures. 

4. Nano-photonic crystal structures. The investigation of novel optical structures based on 

fabrication of 2D diffractive dielectric structures with a precision of a few nanometers. 

The relation between modeling, fabrication on nanometer scale and the resulting control 

over optical properties like diffraction and photonic bandgap in InP based material. 

Investigations into other materials and hybrid combinations (semiconductor/polymers). 

Keywords 

Quantum dots, III-V compound semiconductor, epitaxy, scanning probes, fast laser spectroscopy, 

nanophotonics, photonic crystal structures. 




PhD 6.0 4.8 



20



T. Mano, R. Nötzel, G.J. Hamhuis, T.J. Eijkemans, and J.H. Wolter, “Formation of InAs quantum 

dot arrays on GaAs (100) by self-organized anisotropic strain engineering of a (In,Ga)As superlattice 

template”, Appl. Phys. Lett. 81, p. 1705 – 1707 (2002). 

A. Yakunin, A.Yu. Silov, P.M. Koenraad, W. van Roy, J. De Boeck, J.H. Wolter “Spatial structure of 

an individual acceptor in GaAs”, Phys. Rev. Lett. 92, 216806 (2004) 

D.M. Bruls, J.W.A.M. Vugs, P.M. Koenraad, H.W.M. Salemink, M. Hopkinson, M.S. Skolnick, 

Fei Long, S.P.A. Gill, and J.H. Wolter, “Conclusive determination of the shape and Indium 

distribution of Self-assembled InAs quantum dots”, Appl. Phys. Lett. 81, 1708-10 (2002) 

R. Prasanth, J.E.M. Haverkort, A. Deepthy, E.W. Bogaart, J.J.G.M. van der Tol, E.A. Patent, G. 

Zhao, Q. Gong, P.J. van Veldhoven, R. Nötzel, and J.H. Wolter, “All-optical switching due to statefilling 

in quantum dots”, Appl. Phys. Lett. 84, 4059 (2004). 

Q. Gong, R. Nötzel, P.J. van Veldhoven, T.J. Eijkemans, and J.H. Wolter, “Wavelength tuning of 

InAs quantum dots grown on InP (100) by chemical-beam epitaxy”, Appl. Phys. Lett. 84, p. 275 – 277 

(2004). 

Research highlights 

30 nm 

1 µm 

[0-11] 

[011] 

Well-ordered (In,Ga)As QDs formed by selforganized 

anisotropic strain engineering on a 

GaAs (100) substrate. 

Lateral ordering of semiconductor quantum dots 

(QDs) of high quality in well-defined arrays and 

networks is one of the most challenging tasks for 

today’s nanomaterials science to be fulfilled for the 

realization of future quantum functional devices. 

We have solved the problem of creating ordered 

arrays of (In,Ga)As QDs on GaAs (100) by selforganization. 

In this pioneering work we have 

established a new concept based on self-organized 

anisotropic strain engineering of (In,Ga)As/GaAs 

superlattice templates, which maintains high 

structural and optical quality of the ordered QD 

arrays. During the molecular beam epitaxial growth 

of a (In,Ga)As/GaAs superlattice at elevated 

temperatures, elongated (In,Ga)As QDs develop into very uniform and long quantum wire arrays 

along the [0-11] direction with well-defined lateral periodicity. The accumulation of the anisotropic 

strain field in this superlattice provides a uniform template 

for the ordering of (In,Ga)As QDs grown on top in welldefined 

arrays along [01-1] (Fig. 1). Excellent optical quality 

up to room temperature is established for these QD arrays. 

This breakthrough, thus, allows for novel fundamental 

studies and device operation principles based on single 

and multiple carrier- and photon-, and coherent quantum 

interference effects. 

We have used cross-sectional Scanning Tunneling 

Microscopy to investigate the shape and composition of 

InAs self-assembled quantum dots under various growth 

conditions and in a range of host crystals. In low growth 

rate dots we were the first to prove that a gradient in the 

Indium concentration in InAs quantum dots exists and is 

responsible for the observed exciton polarization. The 

influence of an Indium gradient was also successfully 

related to the shape of the confined electron wavefunction, 

21 

Cross-sectional STM image of a stack of 5 

InAs quantum dots in a GaAs matrix. 

Image size is 55 nm by 55 nm.


which was measured directly by us using STM. Other matters concerning nanostructured 

materials which were addressed by the same technique concern the formation InAs quantum 

rings, the incorporation of nitrogen in InGaNAs layers, the interface quality and lateral 

composition modulation in digital InGaAs/InAlAs/InP quantum well structures and quantum 

cascade laser structures. 


Prof.dr. J.H. Wolter 

Joachim Wolter’s research interests are in the area of materials, components and systems for 

semiconductors and optical communication technology. 

Prof.dr. H.W.M. Salemink 

Huub Salemink is in active in the area of photonic crystals in III/V semiconductors. Photonic 

crystal (PhC) structures for implementation in planar semiconductor waveguides, comprising: 

design, fabrication and analysis of such nanostructures. A novel class of switchable/tunable 

photonic elements via organic/polymer hybrid structures will be investigated by infiltrating the 

holes with an electro-optic active polymer or liquid crystal. 

Dr. R. Nötzel 

Richard Nötzel is involved with epitaxial growth: Lateral ordering of quantum dots and recently 

established a new concept for creating ordered QD-arrays by self-organized epitaxy. The concept is 

based on self-organized anisotropic strain engineering during superlattice growth to produce wellordered 

one-dimensional QD-arrays of excellent optical quality. These materials offer great 

potential for discovering new physical effects based on the controlled quantum mechanical 

interactions in complex fully confined many particle systems. 

Dr. P.M. Koenraad 

Paul Koenraad focuses on Atomic scale assessment of self-assembled nanostructures and 

magnetic impurities. Scanning probes STM, XTM and AFM are used to probe or manipulate 

single charges, photons, excitons and spins. We recently started to study the electronic structure 

of single magnetic impurities as a first step towards the spin manipulation on the atomic scale. 

Dr. J.E.M. Haverkort 

Jos Haverkort is active in the area of Photonic switching: Study of enhanced nonlinear optical 

properties of quantum dots resulting in optical transparency of the ground state transition. Such a 

large absorption change due to state filling with single electron-hole pairs results in a large 

refractive index nonlinearity. 

Dr. A. Silov 

Andrei Silov works on a polarized single photon emitter and Spin-polarization: Realization of 

nano-photonic devices that generate photons one-by-one in a controllable polarization state will be 

a major advancement in quantum optics. Conversion of the electron spin into polarization of the 

single photon can be accomplished in a self-assembled quantum dot. It is our ultimate goal to 

realize a novel opto-spintronic device that generates polarized single photons. 

Dr. R.W. van der Heijden 

Rob van der Heijden works on photonic crystal (PhC) structures for implementation in planar 

semiconductor waveguides, comprising: design, fabrication and analysis of such nanostructures. 

A novel class of switchable/tunable photonic elements via organic/polymer hybrid structures will 

be investigated by infiltrating the holes with an electro-optic active polymer or liquid crystal. 

22



2001 

D.M. Bruls, J.W.A.M. Vugs, P.M. Koenraad, M.S. Skolnick, M. Hopkinson, and J.H. Wolter 

Cracking self-assembled InAs quantum dots Appl. Phys. A 72 (2001) S205 - S207 

B.H.P. Dorren, J.E.M. Haverkort, R. Prasanth, F.H. Groen, and J.H. Wolter Low crosstalk penalty MZI 

Space switch with a 0.64 mm phase shifter using quantum well electrorefraction IEEE Photon. Tech. Lett., 

13 (2001) 37 – 39 

M. Kemerink, J.W. Gerritsen, J.G.H. Hermsen, P.M. Koenraad, H. van Kempen, and 

J.H. Wolter Low-temperature scanning tunneling microscope for luminescence measurements in high 

magnetic fields Rev.Sci. Instrum. 72 (2001) 132 - 135 

M. Kemerink, K. Sauthoff, P.M. Koenraad, J.W. Gerritsen, H. van Kempen, 

V.M. Fomin, J.H. Wolter and J.T. Devreese Optical properties of a tip-induced quantum dot Appl. Phys. A. 

72 (2001) S239 - S242 

A.W.E. Minnaert, A.Yu. Silov, W. van der Vleuten, J.E.M. Haverkort, and J.H. Wolter 

Fröhlich interaction in InAs/GaAs self assembled- quantum dots Phys. Rev. B 63 (2001) 075303, 1 - 4 

R. Nötzel and K.H. Ploog MBE of quantum wires and quantum dots J. Cryst. Growth, 227-228 (2001) 8 – 12 

G.J. de Raad, D.M. Bruls, P.M. Koenraad, and J.H. Wolter STM observations of GaAs (110) showing the top 

and bottom zig-zag rows of the surface Phys. Rev. B 64 (2001) 075314, 1 - 7 

L.J.M. Selen, F.J.J. Janssen, L.J. van IJzendoorn, M.J.J. Theunissen, P.J.M. Smulers, T.J. Eijkemans, and 

M.J.A. de Voigt Ion-channeling analysis of boron clusters in silicon J. Appl. Phys. 90 (2001) 4741 

H. van Zalinge, B. Özyilmaz, A. Böhm, R.W. van der Heijden, J.H. Wolter, and 

P. Wyder Observation of the screening signature in the lateral photovoltage of electrons in the quantum 

Hall regime Phys. Rev. B 64 (2001) 235303, 1 - 4 

H. van Zalinge, B. Özyilmaz, A. Böhm, R.W. van der Heijden, J.H. Wolter, and 

P. Wyder Charge screening in the quantum Hall regime probed by the lateral photoelectric effect Physica B 

298 (2001) 60 - 64 

2002 

F. Alsina, P. V. Santos, H. P. Schönherr, W. Seidel, R. Nötzel, and K. H. Ploog 

Surface-acoustic-wave-induced carrier transport in quantum wires Phys. Rev. B, 66 (2002) 165330 

D.M. Bruls, J.W.A.M. Vugs, P.M. Koenraad, H.W.M. Salemink, M. Hopkinson, M.S. Skolnick, Fei Long, 

S.PA. Gill, and J.H. Wolter Determination of the shape and Indium distribution of low-growth-rate InAs 

quantum dots by cross-sectional scanning tunneling microscopy Appl. Phys.Lett. 81 (2002) 1708 - 1710 

X.Y. Chen and P.M. Koenraad Effects of quantum confinement on low frequency noise in delta-doped GaAs 

structures grown by MBE Fluctuations and Noise Letters 2 (2002) L37 - L45 

J.H. Davies, D.M. Bruls, J.W.A.M. Vugs, and P.M. Koenraad Relaxation of a strained quantum well at a 

cleaved surface J. of Appl. Phys. 91 (2002) 4171 - 4176 

Q. Gong, R. Nötzel, J.H. Wolter, H.-P. Schönherr, and K.H. Ploog Distinct growth behaviours in molecularbeam 

epitaxy of (in, Ga)As on GaAs (3 1 1)A substrate 

J. of Crys. Growth 242 (2002)104 – 108 

Q. Gong, R. Nötzel, G.J. Hamhuis, T. J. Eijkemans, and J. H. Wolter Leveling and rebuilding: an approach 

to improve the uniformity of (In,Ga)As quantum dots Appl. Phys. Lett. 81 (2002) 1887 - 1889 

23


Q. Gong, R. Nötzel, G. J. Hamhuis, T. J. Eijkemans, and J.H. Wolter Self-organized strain engineering on 

GaAs (311)B: Template formation for quantum dot nucleation control Appl. Phys. Lett. 81 (2002) 3254 - 

3256 

M. Kemerink, P. Offermans, P.M. Koenraad, J.K.J. van Duren, R.A.J. Janssen, H.W.M. Salemink, and J.H. 

Wolter Real-space measurement of the potential distribution inside organic semiconductors Phys. Rev. Lett. 

88 (2002) 096803 

R.A. Lewis, P.M. Koenraad, I.V. Bradley, and W. Xu Effect of strong terahertz radiation on 

magnetoconductivity in two dimensions Int. J. Mod. Phys B 16 (2002) 2964 – 2967 

T. v. Lippen, H. Boudinov, H.H. Tan, and C. Jagadish Electrical isolation of AlxGa1-xAs by ion irradiation 

Appl. Phys. Lett. 80 (2002) 264 - 266 

T. Mano, R. Nötzel, G.J. Hamhuis, T.J. Eijkemans, and J.H. Wolter Formation of InAs quantum dot arrays 

on GaAs (100) by self-organized anisotropic strain engineering of a (In,Ga)As superlattice template Appl. 

Phys. Lett. 81 (2002) 1705 – 1707 

G.J. de Raad, D.M. Bruls, P.M. Koenraad, and J.H. Wolter Interplay between tip-induced band bending and 

voltage-dependent surface-corrugation on GaAs-(110) surfaces Phys. Rev. B 64 (2002) 075314/1-7 

2003 

D.M. Bruls, P.M. Koenraad, H.W.M. Salemink, J.H. Wolter, M. Hopkinson, and 

M.S. Skolnick Stacked low-growth-rate InAs quantum dots studied at the atomic level by cross-sectional 

Scanning Tunneling Microscopy Appl. Phys. Letts. 82 (2003) 3758 – 3760 

Q. Gong, R. Nötzel, and J.H. Wolter Strain-driven (In,Ga)As growth instability on GaAs (311)A and (311)B: 

Self-organization of template for InAs quantum dot nucleation control J. of Crys. Growth 251 (2003) 150 - 

154 

S.E.J. Jacobs, M. Kemerink, P.M. Koenraad, M. Hopkinson, H.W.M. Salemink, and J.H. Wolter Spatially 

resolved scanning tunneling luminescence on self-assembled InGaAs/GaAs quantum dots Appl. Phys. Lett. 

83 (2003) 290 – 292 

G. Janssen, E. Goovaerts, A. Bouwen, B. Partoens, B. Van Daele, N. Zurauskiene, P. M. Koenraad, and J. 

H. Wolter Observation of cyclotron resonance in an InAs/GaAs wetting layer with shallowly formed 

quantum dots Phys. Rev. B 68, 045329-6 (2003) 

M. Kemerink, J.K.J. van Duren, P. Jonkheijm, P.M. Koenraad, R.A.J. Janssen, H.W.M. Salemink, en J.H. 

Wolter Relating substitution to single-chain conformation and aggregation in poly (p-phenylene vinylene) 

films Nanoletters 3 (2003) 1191 - 1196 

P. Offermans, P.M. Koenraad, and J.H. Wolter, J.D. Song, Jong Min Kim, Seong Ju Bae, and Yong Tak Lee 

Annealing of InGaAlAs digital alloy studied with scanning-tunneling microscopy and filled-states 

topography Appl. Phys. Letts. 82 (2003) 1191 – 1193 

P. Offermans, P.M. Koenraad, and J.H. Wolter Digital alloy interface grading of an InAlAs/InGaAs 

quantum cascade laser structure studied by cross sectional scanning tunneling microscopy Appl. Phys 

Letts. 83 (2003) 4131 - 4133 

H. van Zalinge, R.W. van der Heijden, and J.H. Wolter Anisotropic Corbino magnetothermopower in a 

quantum Hall system Phys. Rev. B 67 (2003) 165311 1-5 

H.H. Zhan, R. Nötzel, G.J. Hamhuis, T.J. Eijkemans, and J.H. Wolter Low-temperature growth of selfassembled 

InAs dotson GaAs by molecular beam epitaxy J. of Crys. Growth 251 (2003) 135 – 139 

H.H. Zhan, R. Nötzel, G.J. Hamhuis, T.J. Eijkemans, and J.H. Wolter Self-assembled InAs quantum dots 

formed by molecular beam epitaxy at low temperature and post-growth annealing J. of Applied Physics 93 

(2003) 5953 – 5958 

24


2004 

Q. Gong, R. Nötzel, P.J. van Veldhoven, T.J. Eijkemans, and J.H. Wolter Wavelength tuning of InAs 

quantum dots grown on InP (100) by chemical-beam epitaxy Appl. Phys. Letts. 84 (2004) 275 – 277 

Q. Gong, R. Nötzel, P.J. van Veldhoven, T.J. Eijkemans, and J.H. Wolter InAs/InP quantum dots emitting 

in the 1.55 m wavelength region by inserting submonolayer GaP interlayers Appl. Phys. Letts. 85 (2004) 

1404 – 1406 

Q. Gong, P. Offermans, R. Nötzel, P.M. Koenraad, and J.H. Wolter Capping process of InAs/GaAs 

quantum dots studied by cross-sectional scanning tunneling microscopy Appl. Phys. Letts. 85 (2004) 5697 - 

5699 

J. He, R. Nötzel, P. Offermans, P.M. Koenraad, Q. Gong, G.J. Hamhuis, T.J. Eijkemans, and J.H. Wolter 

Formation of columnar (In,Ga)As quantum dots on GaAs (100) Appl. Phys. Letts. 85 (2004) 2771 - 2773 

M. Kemerink, S.F. Alvarado, P. Müller, P.M. Koenraad, H.W.M. Salemink, J.H. Wolter, and R.A.J. Janssen 

Scanning tunneling spectroscopy on organic semiconductors: Experiment and model Phys. Rev. B 70 

(2004) 045202 

T. van Lippen, R. Nötzel, G.J. Hamhuis, and J.H. Wolter Self-organized lattice of ordered quantum dot 

molecules Appl. Phys. Letts. 85 (2004) 118-120 

K.T. Mazon, G.-Q. Hai, M.T. Lee, P.M. Koenraad, and A.F.W. van de Stadt Low-temperature electron 

mobilities due to ionized impurity scattering in multisubband two-dimensional semiconductor systems 

Phys. Rev. B 70 (2004) 193312 

R. Prasanth, J.E.M. Haverkort, A. Deepthy, E.W. Bogaart, J.J.G.M. van der Tol, E.A. Patent, G. Zhao, Q. 

Gong, P.J. van Veldhoven, R. Nötzel, and J.H. Wolter All-optical switching due to state-filling in quantum 

dots Appl. Phys. Letts. 84 (2004) 4059 – 4061 

A.Yu. Silov, P.A. Blajnov, J.H. Wolter, R. Hey, K.H. Ploog, and N.S. Averkiev, Current-induced spin 

polarization at a single heterojunction Appl. Phys. Letts. 85 (2004) 5929 

A.M. Yakunin, A.Yu. Silov, P.M. Koenraad, J.H. Wolter, W. van Roy, J. De Boeck, J.-M. Tang, and M.E. 

Flatté Spatial structure of an individual Mn acceptor in GaAs Phys. Rev. Lett. 92 (2004) 216806 1-4 

H. van Zalinge, R.W. van der Heijden, J.H. Wolter, B. Özyilmaz, A. Böhm, and P. Wyder, Lateral 

photoelectric effect studies of a two-dimensional electron gas under quantum Hall conditions Semicon. Sci. 

Technol. 19 (2004) 1153 - 1160 

R. van der Heijden, M.S.P. Andriesse, C-F Carlstrom, E. van der Drift, E-J Geluk, R.W. van der Heijden, F. 

Karouta, P. Nouwens, Y.S. Oei, T. de Vries, H.W.M. Salemink, Deep dry etching process development for 

photonic crystals in InP-based planar waveguides, Photonic Crystal Materials and Nanostructures, edited by 

R.M. De La Rue, P. Viktorovich, C.M. Sotomayor Torres, M. Midrio, Proceedings of SPIE Vol. 5450 (SPIE, 

Bellingham, WA, 2004) pp 523-532 


25

Nano-engineering / cNM Molecular Materials and Nanosystems 

26


27


Molecular Materials and Nanosystems R.A.J. Janssen 

Functional properties of organic molecules and polymer materials and nanostructures attract 

enormous international attention in contemporary chemistry and physics. This interest is in part 

motivated by a continuing interest for miniaturization and by the numerous opportunities that 

arise for employing molecular electronics and photonics in new and technologically advanced 

applications. In our view fascinating opportunities arise at the crossroads of molecular and bulk 

dimensions, when recent trends in synthetic organic and supramolecular chemistry, polymer 

science, and solid-state physics are combined to create functional nanostructures and 

nanoassemblies. We aim at exploring this emerging field of research, by designing and 

investigating novel molecular, polymer and hybrid materials and structures in which nanoscopic 

dimensions become crucial for macroscopic electrical or optical properties. The prospect that 

nanoscopic functional polymers can be employed in new and technologically advanced 

applications remains one of the long-term goals of our research. 


1. Physics of Nanostructures. We focus on the use of scanning tunneling microscopy for 

studying nanocontacts, in elucidating the mechanism of friction on a nanoscale, and in 

inelastic tunneling spectroscopy to observe vibration spectra of single molecules 

2. PhotoPhysics of Molecular Materials. The temporal evolution of primary photoexcitations in 

molecules, mutichromophoric arrays, nanoaggregates, and composite semiconductors is 

studied with transient (100 fs to 10 ms) optical. Nanostructured photoactive materials are 

developed and utilized to prepare, investigate, and advance the performance of polymer 

solar cells and light-emitting diodes. 

3. Molecular and Polymer Electronics. Focus on spectroscopic characteristics of charge carriers 

and on studying charge transport in single molecules, thin (semi)conducting polymer 

films, and nanostructured composite semiconductor blends. Optimization of chargecarrier 

mobility in semiconducting polymers and establishing the relation with 

morphology is one of the goals. 

Keywords 

Functional molecules and polymers, scanning probe microscopy, ultrafast spectroscopy, charge 

transport, molecular electronics, nanofriction, nanostructured materials, polymer opto-electronic 

devices. 



Senior staff 4 2 

PhD 11.3 9.0 



The group Molecular Materials and Nanostructures participates 60/40 in the TU/e focus areas 

Nano-Engineering and Polymers, and the research contribution to Nano-engineering is 10 fte. 

28



A. Marcos Ramos, M.T. Rispens, J.K.J. van Duren, J.C. Hummelen, and R.A.J. Janssen, 

Photoinduced electron transfer and photovoltaic devices of a conjugated polymer with pendant 

fullerenes, J. Am. Chem. Soc. 123, 6714-6715, (2001) 

M. Kemerink, P. Offermans, J.K.J. van Duren, P.M. Koenraad, R.A.J. Janssen, H.W.M. Salemink, 

J.H. Wolter, Real-space measurement of the potential distribution inside organic semiconductors, 

Phys. Rev. Lett., 88, 096830/1-096830/4, (2002) 

M.M. Wienk, J.M. Kroon, W.J.H. Verhees, J. Knol, J.C. Hummelen, P.A. van Hal, R.A.J. Janssen, 

Efficient methano[70]fullerene / MDMO-PPV bulk heterojunction photovoltaic cells, Angew. 

Chem. Int. Ed., 42, 3371 (2003) 

J. K. J. van Duren , X. Yang , J. Loos, C.W.T. Bulle-Lieuwma, A.B. Sieval, J.C. Hummelen, R.A.J. 

Janssen, Relating the Morphology of Poly(p-phenylene vinylene)/Methanofullerene Blends to 

Solar-Cell Performance, Adv. Funct. Mater., 14, 425-435 (2004) 

E.H.A. Beckers, S.C.J. Meskers, A.P.H.J. Schenning, Z. Chen, F. Würthner, P. Marsal, D. 

Beljonne, J. Cornil, and R.A.J. Janssen, The influence of intermolecular orientation on the 

photoinduced charge transfer kinetics in self-assembled aggregates of donor-acceptor arrays, J. 

Am. Chem. Soc. 128, 649-657 (2006). 


The kinetics of photoinduced charge 

transfer reactions in covalently linked 

donor-acceptor molecules often undergo 

dramatic changes when these molecules 

self assemble from a molecular dissolved 

state into a nanoaggregate. Frequently, 

the origin of these changes is only 

partially understood. We have studied the 

intermolecular spatial organization of 

three homologous arrays, consisting of a 

central perylene bisimide (PERY) 

acceptor moiety and two oligo(pphenylene 

vinylene) (OPV) donor units, 

Cartoon of the two limiting situations for the one-dimensional 

packing of OPV-PERY-OPV arrays to give J-type (left) and Htype 

(right) aggregates 

in nanoaggregates and identify both face-to-face (H-type) and slipped (J-type) stacking of the OPV 

and PERY chromophores. For the J-type aggregates, short intermolecular OPV-PERY distances 

are created that give rise to a charge-transfer absorption band. The proximity of the donor and 

acceptor groups in the J-type aggregates enables a highly efficient photoinduced charge separation 

with a rate (kcs > 1012 s-1) that significantly exceeds the rate of the intramolecular charge transfer 

of the same compounds when molecularly dissolved, even in the most polar media. In the H-type 

aggregates, on the other hand, the intermolecular OPV-PERY distance is not reduced compared to 

the intramolecular separation and, hence, the rates of the electron transfer reactions are not 

significantly affected compared to the molecular dissolved state. Similar to the forward electron 

transfer, the kinetics of the charge recombination in the aggregated state can be understood by 

considering the different inter-chromophoric distances that occur in the H and J-type aggregates. 

These results provide a first consistent rationalization of the remarkable differences that are 

observed for photoinduced charge transfer reactions of donor-acceptor compounds in 

molecularly-dissolved versus aggregated states. 

29



Prof.dr.ir. R.A.J. Janssen 

René Janssen focuses on functional π-conjugated molecules, macromolecules, nanostructures, 

and materials that may find application in advanced technological applications. Synthetic organic 

and polymer chemistry are combined with advanced optical spectroscopy, electrochemistry, 

morphological characterization and the preparation of prototype devices to accomplish these 

goals. 

Dr. C. F. J. Flipse 

Kees Flipse has obtained experience over several years in the following research areas: 

Nanofriction, electronic structure of surfaces and nanostructures by using several experimental 

techniques like scanning probe techniques, photoemission, HREELS in combination with 

theoretical modeling. 

Dr.ir. M. Kemerink 

Martijn Kemerink has experience in the area of low-temperature STM on semiconductor 

quantum dots and wells. More recently he is involved charge transport in organic materials, with 

an emphasis on nano-scale probing of electrical properties using AFM, STM and related 

techniques. Also investigation and visualization of the morphology of conjugated polymers and, 

recently, time-dependent charge transport in organic materials 

Dr. S.C.J. Meskers 

Stefan Meskers studies photo-physical process in molecular materials. Spectroscopic techniques 

used include various types of time-resolved laser methods and circular polarization sensitive 

spectroscopy. Nanostructured functional organic materials comprising conjugated polymers and 

oligomers are investigated with the aim of constructing opto-electronic devices. 


2001 

A.T.M. van. Gogh, C.F.J. Flipse, D.G. Nagengast, E.S. Kooij, N.J. Koeman, J.H. Rector, R.J.J.G.A.M. Smeets, 

R. Griessen, Structural, electrical and optical properties of La 1-zY z H x switchable mirrors. Phys. Rev. B, 63, 

195105-195126,(2001) 

D.T. Balogh, A. Dhanabalan, P. Dynarowicz-Latka, A.P.H.J. Schenning, O.N. Oliveira, E.W. Meijer , R.A.J. 

Janssen, Langmuir films from an oligo(p-phenylene vinylene) functionalized with a diamiontriazine head 

group., Langmuir, 17, 3281-3285, (2001) 

A. Dhanabalan, J.K.J. van Duren, P.A. van Hal, J.L.J. van Dongen, R.A.J. Janssen, Synthesis and 

characterization of a low band gap conjugated polymer for bulk heterojunction photovoltaic cells, Adv. 

Funct. Mater., 11, 255-262, (2001) 

M. Jayakannan, J.L.J. van Dongen, R.A.J. Janssen, Mechanistic aspects of the Suzuki polycondensation of 

thiophenebisboronic derivatives and diiodobenzenes analyzed by MALDI-TOF mass spectrometry, 

Macromolecules, 34, 5386-5393, (2001) 

A. Marcos Ramos, M.T. Rispens, J.L.J. van Duren, J.C. Hummelen, R.A.J. Janssen, Photoinduced electron 

transfer and photovoltaic devices of a conjugated polymer with pendant fullerenes, J. Am. Chem. Soc., 123, 

6714-6715, (2001) 

J.J. Apperloo, R.A.J. Janssen, P.R.L. Malenfant, J.M.J. Fréchet, Interchain delocalization of photoinduced 

neutral and charged states in nanoaggregates of lengthy oligothiophenes, J. Am. Chem. Soc., 123, 6916- 

6924, (2001) 

30


P.A. van Hal, R.A.J. Janssen, G. Lanzani, G. Cerullo, M. Zavelani-Rossi, S. De Silvestri, A two-step 

mechanism for photoinduced electron transfer in an oligo(phenylene vinylene) fullerene dyad, Phys. Rev. B. 

64, 075206/1-075206/7, (2001) 

P.A. van Hal, R.A.J. Janssen, G. Lanzani, G. Cerullo, M. Zavelani-Rossi, S. De Silvestri, Full temporal 

resolution of the two-step photoinduced energy-electron transfer in a fullerene-oligothiophene-fullerene 

triad using sub-10 fs spectroscopy, Chem. Phys. Lett., 345, 33-38, (2001) 

A. El-ghayoury, A.P.J.H. Schenning, P.A. van Hal, J.K.J. van Duren, R.A.J. Janssen, E.W. Meijer, 

Supramolecular hydrogen bonded oligo(p-phenylene vinylene) polymers, Angew. Chem. Int. Ed., 40, 3660- 

3663. (2001); Angew. Chem. 113, 3772-3775, (2001) 

O.J. Korovyanko, R. Österbacka, X.M. Jiang Z.V. Vardeny, R.A.J. Janssen, Photoexcitation dynamics in 

regioregular and regiorandom polythiophene films, Phys. Rev. B., 64, 235122/1-235122/6, (2001) 

2002 

M.V. Tiba, O. Kurnosikov, C.F.J. Flipse, B. Koopmans, H.J.M. Swagten, J.T. Kohlhepp, W.J.M. De Jonge, 

Ordering of organic molecules on passivated reactive substrates: PTCDA on O-p(2 x2)-Ni(1 1 1), Surface 

Science, 498, 161-167, (2002) 

J.J. Apperloo, C. Martineau, P.A. van Hal, J. Roncali, R.A.J. Janssen, Intra- and intermolecular 

photoinduced energy and electron transfer between oligothienylenevinylenes and Nmethylfulleropyrrolidine, 

J. Phys. Chem. A. 106, 21-31, (2002) 

M. Kemerink, P. Offermans, J.K.J. van Duren, P.M. Koenraad, R.A.J. Janssen, H.W.M. Salemink, J.H. 

Wolter, Real-space measurement of the potential distribution inside organic semiconductors, Phys. Rev. 

Lett., 88, 096830/1-096830/4, (2002) 

J.J. Apperloo, B. Groenendaal, H. Verheyen, M. Jayakannan, R.A.J. Janssen, A. Dkhissi, D. Beljonne, R. 

Lazzaroni, J.-L. Brédas, Optical and redox properties of a series of 3,4-ethylenedioxythiophene oligomers, 

Chem. Eur. J., 8, 2384-2396, (2002) 

M. Wohlgennannt, X.M. Jiang, Z.V. Vardeny, R.A.J. Janssen, Conjugation-length dependence of spindependent 

exciton formation rates in π-conjugated oligomers and polymers., Phys. Rev. Lett., 88, 197401/1- 

197401/4, (2002) 

W.J.E. Beek, R.A.J. Janssen, Photoinduced electron transfer in heterosupramolecular assemblies of TiO2 

nanoparticles and terthiophene carboxylic acid in apolar solvents, Adv. Funct. Mater., 12, 519-525, (2002) 

E. Peeters, P.A. van Hal, S.C.J. Meskers, R.A.J. Janssen, E.W. Meijer, Photoinduced electron transfer in a 

liquid crystalline donor-acceptor-donor system, Chem. Eur. J., 8, 4470-4475, (2002) 

J.K.J. van Duren, J. Loos, F. Morrissey, C.M. Leewis, K.P.H. Kivits, L.J. van IJzendoorn, M.T. Rispens, J.C. 

Hummelen, R.A.J. Janssen, In situ compositional and structural analysis of plastic solar cells, Adv. Funct. 

Mater., 12, 665-669, (2002) 

P.A. van Hal, E.H.A. Beckers, S.C.J. Meskers, R.A.J. Janssen, B. Jousselme, P. Blanchard, J. Roncali, 

Orientational effect on the photophysical properties of quaterthiophene-C60 dyads, Chem. Eur. J., 8, 5415- 

5429, (2002) 

S.C.J. Meskers, J.K.J. van Duren, R.A.J. Janssen, Stimulation of electrical conductivity in π-conjugated 

polymeric conductors with infrared light, J. Appl. Phys., 92, 7041, (2002) 

2003 

F. Pedreschi, J. M. Sturm, J. D. O'Mahony, C J. F. Flipse, Magnetic force microscopy and simulations of 

colloidal iron nanoparticles, J. Appl. Phys., 94, 3446-3450, (2003) 

31


G. Tanasa, O. Kurnosikov, C.J.F. Flipse, J.G. Buijnsters, W.J.P. van Enckevort, Diamond deposition on 

modified silicon substrates: Making diamond atomic force microscopy tips for nanofriction experiments, J. 

Appl. Phys., 94, 1699-1704, (2003) 

M.W.G. Ponjee, C.J.F. Flipse, A.W. Denier van der Gon, H. H. Brongersma, Experimental observation of 

vibrational modes on Ag(111) along ΓM and ΓK. Phys. Rev. B 67, 174301/1-174301/5, (2003) 

P.A. van Hal, M.M. Wienk, J.M. Kroon, W.J.H. Verhees, L.H. Slooff, W.J.H. van Gennip, P. Jonkheijm, 

R.A.J. Janssen, Photoinduced electron transfer and photovoltaic response of a MDMO-PPV:TiO2 bulkheterojunction, 

Adv. Mater., 15, 118-121, (2003) 

E.E. Neuteboom, S.C.J. Meskers, P.A. van Hal, J.K.J. van Duren, E.W. Meijer, R.A.J. Janssen, H. Dupin, G. 

Pourtois, J. Cornil, R. Lazzaroni, J.-L. Brédas, D. Beljonne, Alternating oligo(p-phenylene vinylene) - 

perylene bisimide copolymers: Synthesis, photophysics, and photovoltaic properties of a new class of donoracceptor 

materials, J. Am. Chem. Soc., 125, 8625-8638, (2003) 

M. Kemerink, J.K.J. van Duren, P. Jonkheijm, W.F. Pasveer, P.M. Koenraad, R.A.J. Janssen, H.W.M. 

Salemink, J.H. Wolter, Relating substitution to single-chain conformation and aggregation in poly(pphenylene 

vinylene) films, Nano. Lett, 3, 1191-1196, (2003) 

V.D. Mihailetchi, J.K.J. van Duren, P.W.M. Blom, J.C. Hummelen, R.A.J. Janssen, J.M. Kroon, M.T. 

Rispens, W.J.H. Verhees, M.M. Wienk, Electron transport in a methanofullerene, Adv. Funct. Mater. 13, 43- 

46, (2003) 

S.C.J. Meskers, J.K.J. van Duren, R.A.J. Janssen, F. Louwet, L. Groenendaal, Infrared detectors with 

poly(3,4-ethylenedioxy thiophene)/poly(styrene sulfonic acid) (PEDOT/PSS) as the active material, Adv. 

Mater., 15, 613-616, (2003) 

M.M. Wienk, J.M. Kroon, W.J.H. Verhees, J. Knol, J.C. Hummelen, P.A. van Hal, R.A.J. Janssen, Efficient 

methano[70]fullerene / MDMO-PPV bulk heterojunction photovoltaic cells, Angew. Chem. Int. Ed., 42, 

3371-3375., Angew. Chem., 115, 3493-3497, (2003) 

T. Offermans, S.C.J. Meskers, R.A.J. Janssen, Charge recombinbation in a poly(para-phenylene vinylene)fullerene 

derivative composite film studied by transient, non-resonant hole-burning spectroscopy, J. Chem. 

Phys., 119, 10924-10929, (2003) 

2004 

E.H.A. Beckers, S.C.J. Meskers, A.P.H.J. Schenning, Z. Chen, F. Würthner, R.A.J. Janssen, Charge 

separation and recombination in photoexcited oligo(p-phenylene vinylene) - perylene bisimide - arrays close 

to the Marcus inverted region, J. Phys. Chem. A 108, 6933 (2004). 

W.J.E. Beek, M.M. Wienk, R.A.J. Janssen, Efficient hybrid solar cells from ZnO nanoparticles and a 

conjugated polymer, Adv. Mater. 16, 1009 (2004). 

J.K.J. van Duren, X. Yang, J. Loos, C.W.T. Bulle-Lieuwma, A.B. Sieval, J.C. Hummelen, R.A.J. Janssen, 

Relating the morphology of a poly(p-phenylene vinylene): methanofullerene blend to solar cell performance, 

Adv. Funct. Mater. 14, 425 (2004). 

H.H.P. Gommans, M. Kemerink, G.G. Andersson, R.M.T. Pijper, Charge transport and trapping in Csdoped 

poly(diakoxy -p-phenylene vinylene) light-emitting diodes, Phys. Rev. B 69, 155216 (2004). 

M. Kemerink, S.F. Alvarado, F. Muller, P.M. Koenraad, H.W.M. Salemink, J.H. Wolter, R.A.J. Janssen, 

Scanning-tunneling spectoscopy on organic semiconductors: experiment and model, Phys. Rev. B 70, 

045202(2004). 

M. Kemerink, S. Timpanaro, M. de Kok, E.A. Meulenkamp, F.J. Touwslager, Tree-dimensional 

inhomogeneities in PEDOT:PSS Films, J. Phys. Chem. B, 108, 18820 (2004). 

A. Marcos Ramos, S.C.J. Meskers, E.H.A.. Beckers, R.B. Prince, L. Brunsveld, R.A.J. Janssen, 

Supramolecular control over donor-acceptor photoinduced charge separation, J. Am. Chem. Soc. 126, 9630 

(2004). 

32


A. Marcos Ramos, E.H.A. Beckers, T. Offermans, S.C.J. Meskers, R.A.J. Janssen, Photoinduced multistep 

electron transfer in an oligoaniline-oligo(p-phenylene vinylene) - perylene diimide molecular - arrays, J. 

Phys. Chem. A 108, 8201 (2004). 

E.E. Neuteboom, P.A. van Hal, R.A.J. Janssen, Donor-acceptor polymers: A conjugated oligo (p-phenylene 

vinylene) main chain with dangling perylene bisimides, Chem. Eur. J., 10, 3907 (2004). 

F. Würthner, Z. Chen, F.J.M. Hoeben, P. Osswald, C.C. You, P. Jonkheijm, J. van Herrikhuyzen, A.P.H.J. 

Schenning, P.P.A.M. van der Schoot, E.W. Meijer, E.H.A. Beckers, S.C.J. Meskers, R.A.J. Janssen, 

Supramolecular p-n-heterojunctions by co-self-organization of oligo(phenylene vinylene) and perylene 

bisimide dyes, J. Am. Chem. Soc., 126, 10611 (2004) 


C. P. Radano, O.A. Scherman, N. Stingelin-Stutzmann, C. Müller, D. W. Breiby, P. Smith, R. A. J. Janssen, 

and E. W. Meijer, Crystalline-crystalline block copolymers of regioregular poly(3-hexylthiophene) and 

polyethylene by ring-opening metathesis polymerization, J. Am. Chem. Soc., 127, 12502-12503, (2005). 

D. Wasserberg, P. Marsal, S. C. J. Meskers, R. A. J. Janssen, and D. Beljonne, Phosphorescence and triplet 

state energies of oligothiophenes, J. Phys. Chem. B., 109, 4410-4415, (2005). 

J. H. A. Smits, S. C. J. Meskers, R. A. J. Janssen, A. W. Marsman, and D. M. de Leeuw, Two-terminal, 

rewritable memory cells from poly(3-hexylthiophene), Adv. Mater., 17, 1169-1173, (2005). 

M. Kemerink, J. K. J. van Duren, A. J. J. M. van Breemen, J. Wildeman, H. F. M. Schoo, M. M. Wienk, P. 

W. M. Blom, H. F. M. Schoo, and R. A. J. Janssen, Substitution and preparation effects on the molecularscale 

morphology of PPV films, Macromolecules, 38, 7784-7792, (2005). 

X. Yang, S. C. Veenstra, W. J. H. Verhees, M. M. Wienk, R. A. J. Janssen, J. M. Kroon, M. A. J. Michels, and 

J. Loos, Nanoscale morphology of high-performance polymer solar cells, Nano Lett., 5, 579-583, (2005). 

T. Offermans, P. A. van Hal, S. C. J. Meskers, M. M. Koetse, and R. A. J. Janssen, Exciplex dynamics in a 

blend of π-conjugated polymers with electron donating and accepting properties (MDMO-PPV and 

PCNEPV), Phys Rev. B 2005, 72, 045213/1-045213/11, (2005). 

W. J. E. Beek, M. M. Wienk, M. Kemerink, X. Yang, and R. A. J. Janssen, Hybrid zinc oxide - conjugated 

polymer bulk heterojunction solar cells,J. Phys. Chem B., 109, 9505-9516, (2005). 

E. H. A. Beckers, P. Jonkheijm, A. P. H. J. Schenning, S. C. J. Meskers, and R. A. J. Janssen, 

Charge transfer in supramolecular co-aggregates of oligo(p-phenylene vinylene) and perylene bisimide in 

water, ChemPhysChem, 6, 2029-2031, (2005). 

H. H. P. Gommans, M. Kemerink, J. M. Kramer, and R. A. J. Janssen, Field and temperature dependence 

of the photocurrent in polymer:fullerene bulk heterojunction solar cells, Appl. Phys. Lett., 87, 122104/1- 

122104/3, (2005). 

H.H.P. Gommans, M. Kemerink, and R.A.J. Janssen, Negative capacitances in low-mobility solids 

Phys. Rev. B., 72, 235204/1-235204/6 (2005). 

33

Nano-engineering / cNM Theoretical and Polymer Physics 

Theoretical and Polymer Physics M.A.J. Michels 

The leading scientific theme for the research group on theoretical and polymer physics is the 

understanding and prediction, on the basis of the underlying fundamental physics, of the triangle 

relation that exists for polymers between (i) the molecular and mesoscopic structure, (ii) the 

dynamics of microstructure development, and (iii) the material properties. Specific subprogrammes 

have been chosen: (1) electronic and electro-optical properties of functional 

polymers, (2) self-organisation and large-scale structure development, and (3) the physics of 

polymer dynamics and micromechanics. Many of the methods and physical phenomena in these 

areas are not limited to polymers, but have their analogies in wider classes of organic materials 

that are of importance to nanotechnology (e.g. oligomers, colloids, liquid crystals). Where this will 

lead to synergy such other materials may be included in the programme as well. 


1. Electronics and electro-optics. Band gaps and excitons in conjugated polymers. Electronphonon 

coupling in polymers and oligomer crystals. Band conduction vs. hopping 

conduction. Microscopic disorder vs. charge mobility. Development of ab-initio tools. 

2. Self-organisation and structure development. Self-assembly of discotic and chiral molecules. 

Local dynamics of hydrogen-bonded polymers. Polymer crystallization in external fields. 

Mesoscale dynamics and phase separation. Dendrimers and hyperbranched polymers. 

3. Dynamics and micromechanics. Polymer dynamics and deformation at the nanoscale. 

Multiscale modeling. Statistical physics of fracture. 

Keywords 

Conjugated polymers and crystals, band structure, excitations, mobility, ab-initio calculation. Selforganisation, 

discotics, liquid crystals. Polymer dynamics and micromechanics, scale jumping. 




PhD 6.5 5.2 



The group Polymer Physics participates 50/50 in the TU/e focus areas Nano-Engineering and 

Polymers, and the research contribution to Nano-engineering is 5.1 fte. 


J.-W. van der Horst, P.A. Bobbert, M.A.J. Michels, G. Brocks, P.J. Kelly, Ab-initio calculation of the 

electronic and optical excitations in polythiophene: effects of intra- and interchain screening, Physical 

Review Letters 83, 4413-4416, (1999) 

W.A. Schoonveld, J. Wildeman, D. Fichou, P.A. Bobbert, B.J. van Wees, T.M. Klapwijk, 

Coulomb blockade transport in single-crystal organic thin-film transistors, Nature 404, 977 (2000) 

34


K. Hannewald, P.A. Bobbert, Theory of small-polaron band conduction in ultrapure organic crystals, 

Applied Physics Letters 85, 1535-1537 (2004) 

W.F. Pasveer, J. Cottaar, C. Tanase, R. Coehoorn, P.A. Bobbert, P.W.M. Blom, D.M. de Leeuw, 

M.A.J.Michels, Unified description of charge-carrier mobilities in disordered semiconducting polymers, 

Physical Review Letters, 94, 206601 (2005) 

P. van der Schoot, R. Bruinsma, Electrostatics and the assembly of an RNA virus, Physical Review E, 

71, 061928 1-12 (2005) 


Charge-carrier mobilities in disordered 

semiconducting polymers: Fundamental 

understanding of charge-carrier mobilities in 

disordered semiconducting polymers is of 

crucial importance for the further 

development of various devices based on 

these materials, such as light-emitting diodes, 

photovoltaic cells, and transistors. Because of 

the disorder, the transport states in these 

materials are localized at specific sites and 

charge transport takes place by hopping of 

charge carriers (electrons/holes) from site to 

site. In polymer light-emitting diodes, where 

the number of carriers per site is typically 

very low (10 -5 -10 -4 ), the mobilities have always 

assumed to have a strong dependence on the 

temperature and the electric field. The 

concept of correlated disorder was put 

forward to explain the strong dependence on 

35 

Fig. 1 Experimental and calculated current-voltage 

characteristics of a hole-only diode of NRS-PPV 

(thickness L). The effects of the taking into account the 

dependences of the mobility µ on temperature T, 

density p and electric field E is demonstrated. 

the electric field. However, in these devices it is experimentally very difficult to distinguish a 

dependence of the mobility on the electric field from a possible dependence on the charge-carrier 

density, since at higher voltages (electric fields) more charge carriers are injected in the device. 

Recently, we demonstrated that the current-voltage characteristics of polymer diodes can be very 

well described assuming an uncorrelated Gaussian energy disorder of the hopping sites and a, 

numerically or analytically determined, dependence of the mobility on the charge-carrier density. 

The reason for the unexpected dependence on the carrier density at such low densities is the fact 

that at the relevant temperatures the carriers are energetically located in the low-energy tail of the 

Gaussian density of states, such that state-filling effects are still important. Only at very high 

voltages the dependence of the mobility on the electric field becomes relevant. In line with recent 

experimental observations we come to the conclusion that the previously assumed dependence of 

the mobility on electric field in diodes is, for a large part, actually a density-dependence. The work 

has led to two DPI thesis awards (Tanase, Pasveer) and an editorial citation in Nature Materials 

(W.F. Pasveer, J. Cottaar, C. Tanase, R. Coehoorn, P.A. Bobbert, P.W.M. Blom, D.M. de Leeuw, 

and M.A.J. Michels, Phys. Rev. Lett. 94, 206601 (2005)). 


Prof.dr. M.A.J. Michels 

Theoretical physicist with background in statistical physics and experience in application inspired 

and industry-related research. Main current interests: physics of disorder and percolation, 

hopping transport, pattern formation and fractality, gel formation and glassy dynamics. Active in 

the TU/e priority areas of Nano-engineering and Polymer Science and Technology.


Dr. P.A. Bobbert 

Theoretical solid-state physicist, with experience both in the development and application of 

physics-based ab-initio computational tools. Main current interests: the energetics of charged and 

optical excitations in conjugated materials, dynamics of their coupling to phonons and orderdisorder 

transitions, and their mobility in disordered, supramolecular and crystalline materials. 

Mainly active in the TU/e priority area of Nano-engineering. 

Dr. A.V. Lyulin 

Theoretical polymer physicist with experience in large-scale molecular-dynamics and browniandynamics 

simulations. Mainly active in the TU/e priority area of Polymer Science and 

Technology, but contributing ad-hoc with his simulation expertise to studies within Nanoengineering. 

Dr.ir. P.P.A.M. van der Schoot 

Theoretical chemist with background in soft-matter physics and experienced in applying analytical 

theories to colloids, liquid crystals and polymers. Main current interests: ordering and growth 

phenomena in chiral supramolecular aggregates, pattern formation in colloid and liquid-crystal 

mixtures, also in the biological world. Mainly active in the TU/e priority area of Polymer Science 

and Technology, with occasional contributions to Nano-engineering. 


2001 

H.J. Tromp, P. van Gelderen, P.J. Kelly, G. Brocks, P.A. Bobbert, CaB6: a new semiconducting material for 

spin electronics, Physical Review Letters 87, 16401-16405, (2001) 

J. van Gestel, P. van der Schoot, M.A.J. Michels, Helical transition of polymer-like assemblies in solution, 

Journal of Physical Chemistry B 105, 10691-10699, (2001) 

J.-W. van der Horst, P.A. Bobbert, P.H.L. de Jong, M.A.J. Michels, G. Brocks, L.D.A. Siebbeles, J.M. 

Warman, G. Gelinck, Predicting polarizabilities and lifetimes of excitons on conjugated polymer chains, Chemical 

Physics Letters 334, 303-308, (2001) 

J.-W. van der Horst, P.A. Bobbert, M.A.J. Michels, H. Baessler, Calculation of excitonic properties of 

conjugated polymers using the Bethe-Salpeter equation, Journal of Chemical Physics 114, 6950-6959, (2001) 

H.B. Brom, M.A.J. Michels, Percolation and high-frequency hopping in cluster compounds and polymers, 

Philosophical Magazine B 81, 941-954, (2001) 

2002 

P. van Gelderen, P.A. Bobbert, P.J. Kelly, G. Brocks, R. Tolboom, Parameter-free calculation of single-particle 

electronic excitations in YH3, Physical Review B 66, 075104-1-075104-13, (2002) 

J.-W. van der Horst, P.A. Bobbert, M.A.J. Michels, Electronic and optical excitations in crystalline conjugated 

polymers, Physical Review B 66, 035206, (2002) 

J.-W. van der Horst, P.A. Bobbert, W.F. Pasveer, M.A.J. Michels, G. Brocks, P.J. Kelly, Excitons in conjugated 

polymers from first principles, Computer Physics Communications 147, 331-334, (2002) 

S.F. Alvarado, S. Barth, H. Baessler, U. Scherf, J.-W. van der Horst, P.A. Bobbert, M.A.J. Michels, Spatially 

resolved STM spectroscopy of charge injection at the ladder-type poly (paraphenylene) /Au (111) interface, 

Advanced Functional Materials 12, 117-122, (2002) 

P. van der Schoot, Self-assembly of globular particles in a nematic dispersion, Journal of Chemical Physics 117, 

3537-3540, (2002) 

36


2003 

N.C. Greenham, P.A. Bobbert, Two-dimensional electron-hole capture in organic heterojunction light-emitting 

diodes, Physical Review B 68, 245301-245309, (2003) 

J. van Gestel, P. van der Schoot, M.A.J. Michels, Amplification of chirality in helical supramolecular polymers, 

Macromolecules 36, 6668-6673, (2003) 

K. Hannewald, V.M. Stojanovic, J.M.T. Schellekens, P.A. Bobbert, Theory of bandwidth narrowing in oligoacene 

crystals, Synthetic Metals 137, 891-892, (2003) 

W.F. Pasveer, P.A. Bobbert, M.A.J. Michels, B.M.W. Langeveld-Voss, H.F.M. Schoo, J.J.A.M. Bastiaansen, 

Ab-initio study of energy level alignments in polymer-dye blends, Chemical Physics Letters 381-382, (2003) 

H.C.F. Martens, N. Hulea, I. Romijn, H.B. Brom, W.F. Pasveer, M.A.J. Michels, Understanding the doping 

dependence of the conductivity of conjugated polymers: Dominant role of the increasing density of states and 

growing delocalization, Physical Review B 67, 121203-1-121203-4, (2003) 

2004 

K. Hannewald, V.M. Stojanovic, J.M.T. Schellekens, P.A. Bobbert, G. Kresse, and J. Hafner, Theory of 

polaron bandwidth narrowing in organic molecular crystals, Phys. Rev. B. 69, 075211-1-075211-7, (2004) 

K. Hannewald, P.A. Bobbert, Anisotropy effects in phonon-assisted charge-carrier transport in organic molecular 

crystals, Physical Review B 69, 075212-1-075212-12, (2004) 

K. Hannewald, P.A. Bobbert, Ab-initio theory of charge-carrier conduction in ultrapure organic crystals, 

Applied Physics Letters 85, 1535-1537, (2004) 

V.M. Stojanovic, P.A. Bobbert, M.A.J. Michels, Nonlocal electron-phonon coupling: Consequences for the nature 

of polaron states, Physical Review B 69, 144302-1-144302-13, (2004) 

W.F. Pasveer, P.A. Bobbert, M.A.J. Michels, Temperature and field dependence of the mobility in 1D for a 

gaussian density of states, Physica Status Solidi c 1, 164-167, (2004) 

S.V. Lyulin, L.J. Evers, P. van der Schoot, A.A. Darinskii, A.V. Lyulin, M.A.J. Michels, Effect of solvent quality 

and electrostatic interactions on size and structure of dendrimers. Brownian dynamics simulation and mean-field 

theory, Macromolecules 37, 3049-3063, (2004) 

J. van Gestel, P. van der Schoot, M.A.J. Michels, Amplification of chirality in helical supra-molecular polymers 

beyond the long-chain limit, Journal of Chemical Physics 120, 8253-8261, (2004). Also selected for the Virtual 

Journal of Nanoscale Science and Technology 9, April 26, (2004), and for the Virtual Journal of Biological 

Physics Research 7, April 15, (2004) 

S.V. Lyulin, A.A. Darinskii, A.V. Lyulin, M.A.J. Michels, Brownian dynamics of neutral and charged 

dendrimers, Macromolecules 37, 4676-4685, (2004) 

F. Wuerther, Z. Chen, F.J.M. Hoeben, P. Osswald, C.-C. You, P. Jonkheijm, J. van Herrikhuyzen, A.P.H.J. 

Schenning, P.P.A.M. van der Schoot, E.W. Meijer, E.H.A. Beckers, S.C.J. Meskers, R.A.J. Janssen, 

Supramolecular p-n heterojunctions by co-selforganization of oligo(p-phenylene vinylene) and perylene bisimide 

dyes, Journal of the American Chemical Society 126, 10611-10618, (2004) 

X. Yang, J.K.J. van Duren, R.A.J. Janssen, M.A.J. Michels, J. Loos, Morphology and thermal stability of the 

active layer in a poly(p-phenylenevinylene)/methanofullerene plastic photovoltaic devices, Macromolecules 37, 

2151-2158, (2004) 


K. Hannewald, P.A. Bobbert, Nonperturbative theory of exciton-phonon resonances in semiconductor 

absorption, Physical Review B, 72, 113202 (2005) 

S.V. Lyulin, A.A. Darinskii, A.V. Lyulin, M.A.J. Michels, Computer simulation of complexes of dendrimers 

with linear polyelectrolytes, Macromolecules, 38, 3990 (2005) 

37


K.D. Meisel, H. Vocks, P.A. Bobbert, Polarons in semiconducting polymers: study within an extended 

Holstein model, Physical Review B, 71, 205206 (2005) 

T. Mulder, A.V. Lyulin, P. van der Schoot, M.A.J. Michels, Architecture and conformation of uncharged and 

charged hyperbranched polymers: computer simulation and mean-field theory, Macromolecules, 38, 996- 

1006 (2005) 

W.F. Pasveer, P.A. Bobbert, H.P. Huinink, M.A.J. Michels, Scaling of current distributions in variablerange 

hopping transport on two- and three-dimensional lattices, Physical Review B, 72, 174204 (2005) 

W.F. Pasveer, J. Cottaar, C. Tanase, R. Coehoorn, P.A. Bobbert, P.W.M. Blom, D.M. de Leeuw, 

M.A.J.Michels, Unified description of charge-carrier mobilities in disordered semiconducting polymers, 

Physical Review Letters, 94, 206601 (2005) 

R. Coehoorn, W.F. Pasveer, P.A. Bobbert, M.A.J. Michels, Charge-carrier concentration dependence of the 

hopping mobility in organic materials with Gaussian disorder, Physical Review B, 72, 155206 (2005) 

P. van der Schoot, R. Bruinsma, Electrostatics and the assembly of an RNA virus, Physical Review E, 71, 

061928 1-12 (2005) 

X.N. Yang, A. Alexeev, M.A.J. Michels, J. Loos, Effect of spatial confinement on the morphology evolution 

of thin poly(p-phenylenevinylene)/methanofullerene composite films, Macromolecules, 38, 4289-4295 

(2005) 

X. Yang, J. Loos, S.C. Veenstra, W.J.H. Verhees, M.M.Wienk, J.M. Kroon, M.A.J. Michels, R.A.J. Janssen, 

Nanoscale morphology of high-performance polymer solar cells, Nano Letters, 5, 579-583 (2005) 

38

Nano-engineering / cNM Macromolecular Chemistry and Nanoscience 

39


Macromolecular Chemistry and Nanoscience U.S. Schubert 

The program focuses on the design and preparation of (macro)molecules, assemblies, micelles, 

nanoparticles and nano-structured objects utilizing well-defined building blocks in combination 

with covalent and non-covalent (supramolecular) bonds and interactions. For this purpose, living 

and controlled polymerization methods are utilized in order to prepare suitable functionalized 

telechelics and (block) copolymers. The introduction of non-covalent binding motifs is either 

performed on the level of the initiators and monomers or by end-group modification of the 

telechelics and (block) copolymers. Besides synthetic polymers also defined biopolymers, such as 

proteins or DNA, and nanoparticles are utilized. The fabrication of suitable nano- and microstructured 

surfaces is performed utilizing a combination of chemical self-assembly processes, 

nano-lithography (based on scanning probe techniques) and inkjet printing techniques. The 

selective and controlled build-up of functional nanostructures is characterized by a combination 

of optical profiling methods, AFM, STM and TEM with spectroscopic methods. In addition, 

scanning probe methods are also used for the investigation of selected properties of the obtained 

systems (e.g. force spectroscopy, local conductivity measurements, etc.) and for manipulation on 

the nanoscale. 


1. Engineering with macromolecules utilizing covalent and non-covalent interactions. The design 

and synthesis of complex functional macromolecular architectures represents one of the 

main challenges in present research. In particular the introduction of “non-covalent” 

interactions into tailor-made macromolecules seems to be highly promising. By this 

approach, novel “smart” or “intelligent” materials can be designed utilizing the 

reversibility of the non-covalent interactions. 

2. Self-assembled architectures, nanolithography & nanochemistry. Scanning probe microscopy 

tools are being utilized in order to characterize and manipulate objects and structures on a 

nanometer scale. Using scanning probe oxidation well-defined functionalised nanopatterned 

substrates can be prepared that can be subsequently used as templates in a large 

number of chemical (covalent and non-covalent) surface modification routines. A 

combination of automated scanning probe microscopy and oxidation by means of 

patterned electrodes is employed to functionalize surfaces with larger dimensions. 

3. Combinatorial material research and high-throughput experimentation (CMR&HTE). The 

utilization of combinatorial methods, high-throughput screening tools, data evaluation 

and modelling approaches allow a new detailed inside into structure-property as well as 

structure-function relationships. As a result, the selective design of new materials and a 

dramatically improved understanding of the underlying chemical and physical processes 

can be obtained. 

4. Inkjet printing of functional materials. Inkjet printing is used to deposit a large variety of 

materials can be deposited. The technique is used in combination with the CMR&HTE 

program for the preparation of surface libraries as well as for the preparation for devices 

with micrometer precision. Applications are currently found in LED-preparation, printing 

of conductive 2D-tracks as well as three dimensional structures by multi-layers printing. 

Keywords 

Non-covalent assemblies, tailor-made macromolecules, nano-lithography, nano-manipulation, 

nanochemistry, supramolecular chemistry, inkjet printing 




PhD 12.0 9.0 

40




The group Macromolecular Chemistry and Nanoscience participates 50/50 in the TU/e focus 

areas Nano-Engineering and Polymers. 


B.G.G. Lohmeijer, U.S. Schubert, Supramolecular engineering with macromolecules: A novel approach to 

block copolymers, Angew. Chem. Int. Ed., 41, 3825-3829, (2002) 

M. Kudera, C. Eschbaumer, H.E. Gaub, U.S. Schubert, Analysis of metallo-supramolecular systems 

utilizing single-molecule force spectroscopy. Adv. Funct. Materials., 13, 615-620, (2003) 

B.G.G. Lohmeijer, D. Wouters, Z. Yin, U.S. Schubert, Metallo-Supramolecular Block Copolymer Libraries: 

Modular Versatility of the LEGO-System, Chem. Commun. 2886 (2004) 

S. Hoeppener, U.S. Schubert, Magnetic nanostructures – fabrication via the electrochemical oxidation of 

self-assembled monolayers and site-selective derivatization of these surface templates. Small 1, 628 (2005) 

D. Wouters, R. Willems, S. Hoeppener, C.F.J. Flipse, U.S. Schubert, Oxidation conditions for octadecyl 

trichlorosilane monolayers on silicon: a detailed AFM-study of the effects of pulse-height and duration on 

the oxidation of the monolayer and the underlying Si-substrate. Adv. Funct. Mater. 15, 938 (2005) 


Nanolithography and nanochemistry: 

The obtainable size of devices 

produced by photolithography 

techniques is limited. Therefore, 

other patterning techniques are 

intensively studied in order to create 

smaller structures. Dip-pen, 

dynamic plow and oxidative probe 

lithography are examples of 

scanning probe based patterning 

techniques. The last of which is 

especially interesting because it is 

allows for both high resolution 

patterning (up to 10 nm) as well as 

chemical and physical modification 

of these structures due to 

differences in local properties 

between the oxidized and unaffected 

areas (e.g. surface charge, solubility, 

reactivity). Our group demonstrated 

the use of octadecyltrichloro silane 

(OTS) monolayers on silicon 

Example of surface modification electrooxidative defined 

templates. Starting from the top in a clockwise direction the 

images demostrate the selective assembly of: carbon nanotubes, exsitu 

formed nanoparticels, molecular bilayers, multicomponent 

structures, in-situ formed metal particles and large scale oxidation 

b d 

substrates as a versatile starting platform for a number of modification routes. The local oxidation 

of OTS converts the terminal methyl groups of the monolayer into carboxylic acid groups, 

introducing functionality that can be later decorated by, but is not limited to, quaternary 

ammonium salts and positively charged particles (see example images). The modification of the 

templates with for example amines, or their conversion to acid anhydrides and the coupling of 

initiators as well as dyes or bio-material allows for the designed production of nanometer-sized 

electronic devices but also the formation of devices involving (bio)molecular recognition and 

sensor devices. Moreover the oxidation and local functionalization procedure can be repeated in a 

sequential fashion, enabling the build-up of complex multi-component devices. Due to the 

41


increasing progress in the development of automated and multi-tip scanning probe systems the 

fast modification of large-scale samples (square centimeters) becomes feasible. 


Prof. Dr. U.S. Schubert 

Ulrich Schubert focuses on self-organizing supramolecular architectures and materials. 

Synthetic organic chemistry is combined with macromolecular and supramolecular chemistry in 

order to design and synthesize new molecules, polymers and materials. Utilizing advanced 

characterization methods in solution, in bulk and on surfaces the nanoscopic and mesoscopic 

properties are investigated in detail. 


2001 

U.S. Schubert, C. Eschbaumer, Functionalized oligomers and copolymers with metal complexing 

segments based on 2,2':6',2''-terpyridines. Macromol. Symp. 163, 177 (2001) 

R. Kröll, C. Eschbaumer, U.S. Schubert, M.R. Buchmeiser, K. Wurst, Access to heterogeneous atomtransfer 

radical polymerization (ATRP) catalysts based on dipyridylamine and terpyridine via ring-opening 

metathesis polymerization (ROMP). Macromol. Chem. Phys. 202, 645 (2001) 

U.S. Schubert, Towards the design of novel macromolecules. Chem. Engineer. News 79, 221 (2001) 

U.S. Schubert, C. Eschbaumer, P.R. Andres, H. Hofmeier, C.H. Weidl, E. Herdtweck, E. Dulkeith, A. 

Morteani, N. Hecker, J. Feldmann, 2,2':6',2''-Terpyridine metal complexes as building blocks for extended 

functional metallo-supramolecular assemblies and polymers. Synth. Metals 121, 1249 (2001) 

U.S. Schubert, G. Hochwimmer, Biodegradable polymers with specific metal binding sites based on 

bipyridine containing poly(lactid acid) and poly(ε-caprolactone): Towards high molecular weight 

polyesters. Macromol. Rapid Commun. 22, 274 (2001) 

M.R. Buchmeiser, R. Kröll, K. Wurst, T. Schareina, R. Kempe, C. Eschbaumer, U.S. Schubert, Polymersupported 

polymerization catalysts via ROMP. Macromol. Symp. 164, 187 (2001) 

U.S. Schubert, C. Eschbaumer, O. Hien, P.R. Andres, 4'-Functionalized 2,2':6',2''-terpyridines as building 

blocks for supramolecular chemistry and nanoscience. Tetrahedron Lett. 42, 4705 (2001) 

G. Billancia, D. Wouters, A.A. Precup, U.S. Schubert, Towards functionalized nanoparticles. Polymeric 

Materials: Science & Engineering 85, 508 (2001) 

M. Heller, U.S. Schubert, Optically active supramolecular terpyridine end-capped poly(L-lactide)s. 

Macromol. Rapid Commun. 22, 1362 (2001) 

U.S. Schubert, M. Heller, Metallo-supramolecular initiators for the preparation of novel functional 

architectures. Chem. Eur. J. 7, 5252 (2001) 

2002 

U.S. Schubert, C. Eschbaumer, Macromolecules containing bipyridine and terpyridine metal complexes: 

Towards metallo-supramolecular polymers. Angew. Chem. Int. Ed. 41, 2892 (2002) 

T. Salditt, U.S. Schubert, Layer-by-layer self-assembly of supramolecular and biomolecular films. Reviews 

Mol. Biotech. 90, 55 (2002) 

M. Heller, U.S. Schubert, Poly(styrene) with pendant mixed functional ruthenium(II)-terpyridine 

complexes. Macromol. Rapid Commun. 23, 411 (2002) 

42


H. Hofmeier, U.S. Schubert, Metallo-supramolecular graft copolymers: A novel approach for 

polymeranalogous reactions. Macromol. Rapid Commun. 23, 561 (2002) 

M. Heller, U.S. Schubert, Multi-functionalized 2,2':6',2''-terpyridines. Synlett. 751 (2002) 

J.-F. Gohy, B.G.G. Lohmeijer, U.S. Schubert, Metallo-supramolecular block copolymer aqueous micelles 

containing a soft core. Macromol. Rapid Commun. 23, 555 (2002) 

J.-F. Gohy, B.G.G. Lohmeijer, U.S. Schubert, Metallo-supramolecular block copolymer micelles. 

Macromolecules 35, 4650 (2002) 

B.G.G. Lohmeijer, U.S. Schubert, Supramolecular engineering with macromolecules: A novel approach to 

block copolymers. Angew. Chem. Int. Ed. 41, 3825 (2002) 

M. Heller, U.S. Schubert, Functionalized 2,2'-bipyridines and 2,2':6',2''-terpyridines via Stille-tpye crosscoupling 

procedures. J. Org. Chem. 67, 8269 (2002) 

J.-F. Gohy, B.G.G. Lohmeijer, S.K. Varshney, B. Decamps, E. Leroy, S. Boileau, U.S. Schubert, Stimuliresponsive 

aqueous micelles made from an ABC metallo-supramolecular triblock copolymer. 


2003 

D. Wouters, S. Höppener, L. Chi, H. Fuchs, U.S. Schubert, Highly ordered self-assembled architectures of 

modified terpyridines on HOPG imaged by STM. Adv. Funct. Mater. 13, 277 (2003) 

A. El-ghayoury, H. Hofmeier, B. de Ruiter, U.S. Schubert, Combining covalent and non-covalent crosslinking: 

A novel terpolymer for two-step curing applications. Macromolecules 36, 3955 (2003) 

R. Hoogenboom, D. Wouters, U.S. Schubert, L-Lactide polymerization utilizing a hydroxy-functionalized 

3,6-bis(2-pyridyl)-pyridazine as supramolecular (co)initiator: The construction of polymeric [2×2] grids. 


J.-F. Gohy, B.G.G. Lohmeijer, U.S. Schubert, From supramolecular block copolymers to advanced nanoobjects. 

Chem. Eur. J. 9, 3472 (2003) 

M. Kudera, C. Eschbaumer, H.E. Gaub, U.S. Schubert, Analysis of metallo-supramolecular systems 

utilizing single-molecule force spectroscopy. Adv. Funct. Materials. 13, 615 (2003) 

D. Wouters, U.S. Schubert, Constructive nanolithography and nanochemistry: Local probe oxidation and 

chemical modification. Langmuir 19, 9033 (2003) 

P.R. Andres, R. Lunkwitz, G.R. Pabst, K. Böhn, D. Wouters, S. Schmatloch, U.S. Schubert, New 4'functionalized 

2,2':6',2''-terpyridines for applications in macromolecular chemistry and nanoscience. Eur. 

J. Org. Chem. 3769 (2003) 

M. Al-Hussein, B.G.G. Lohmeijer, U.S. Schubert, W.H. de Jeu, The melt morphology of polystyrene 

polyethylene oxide metallo-supramolecular diblock copolymer. Macromolecules 18, 9281 (2003) 

S. Schmatloch, A.M.J. van den Berg, A.S. Alexeev, H. Hofmeier, U.S. Schubert, Soluble high molecular 

mass poly(ethylene oxide)s via self-organization, Macromolecules 36, 9943 (2003) 

R. Hoogenboom, G. Kickelbick, U.S. Schubert, Synthesis and characterization of novel substituted 

3,6-bis(2-pyridyl)-pyridazine metal coordinating ligands. Eur. J. Org. Chem. 4887 (2003) 

2004 

H. Hofmeier, A. El-ghayoury, A.P.H.J. Schenning, U.S. Schubert, New Supramolecular Polymers 

Containing both Terpyridine Metal Complexes and Quadruple Hydrogen Bonding Units, Chem. 

Commun. 318 (2004) 

D. Wouters, U.S. Schubert, Nanolithography and Nanochemistry: Probe Related Patterning Techniques 

and Chemical Modification for Nanometer-sized Devices, Angew. Chem. Int. Ed. 43, 2480 (2004) 

43


P.R. Andres, U.S. Schubert, Formation of Metallo-Polymers and –Macrocycles by Complexation of Alkyl- 

Linked Di-Terpyridines with Iron(II) Ions, Synthesis 1229 (2004) 

P.R. Andres, U.S. Schubert, New Functional Polymers and Materials based on 2,2':6',2'' Terpyridine 

Metal Complexes, Adv. Mater. 16, 1043 (2004) 

J.-F. Gohy, B.G.G. Lohmeijer, A. Alexeev, X.-S. Wang, I. Manners, M.A. Winnik, U.S. Schubert, 

Cylindrical Micelles from the Aqueous Self-Assembly of an Amphiphilic Poly(ethylene oxide)-b- 

Poly(ferrocenylsilane) (PEO-b-PFS) Block Copolymer with a Metallo-supramolecular Linker at the Block 

Junction, Chem. Eur. J. 10, 4315 (2004) 

G. Mayer, V. Vogel, B.G.G. Lohmeijer, J.-F. Gohy, J.A. van den Broek, W. Haase, U.S. Schubert, D. 

Schubert, Metallo-supramolecular Block Copolymer Micelles: Improved Preparation and Characterization, 

J. Polym. Sci.: Part A: Polym. Chem. 42, 4458 (2004) 

H. Hofmeier, J. Pahnke, C.H. Weidl, U.S. Schubert, Combined biotin-terpyridine systems: A new versatile 

bridge between biology, polymer science and metallo-supramolechular chemistry, Biomacromolecules 5, 

2055 (2004) 

B.-J. de Gans, U.S. Schubert, Ink-jet Printing Well Defined Polymer Dots and Arrays, Langmuir 20, 7789 

(2004) 

B.G.G. Lohmeijer, D. Wouters, Z. Yin, U.S. Schubert, Metallo-Supramolecular Block Copolymer Libraries: 

Modular Versatility of the LEGO-System, Chem. Commun. 2886 (2004) 

MA.R. Meier, J.-F. Gohy, C.-A. Fustin, U.S. Schubert, Combinatorial Synthesis of Star Shaped Block 

Copolymers: Host-Guest Chemistry of Unimolecular Reversed Micelles, J. Am. Chem. Soc. 126, 11517 

(2004) 


D. Wouters, R. Willems, S. Hoeppener, C.F.J. Flipse, U.S. Schubert, Oxidation conditions for octadecyl 

trichlorosilane monolayers on silicon: a detailed afm-study of the effects of pulse-height and duration on 

the oxidation of the monolayer and the underlying si-substrate. Adv. Funct. Mater. 15, 938 (2005) 

E. Tekin, E. Holder, V.N. Marin, B.-J. de Gans, U.S. Schubert, Inkjet printing of luminescent ruthenium- 

and iridium-containing polymers for applications in light-emitting devices. Macromol. Rapid Commun. 

26, 293 (2005) 

S. Hoeppener, U.S. Schubert, Magnetic nanostructures – fabrication via the electrochemical oxidation of 

self-assembled monolayers and site-selective derivatization of these surface templates. Small 1, 628 (2005) 

M.A.R. Meier, U.S. Schubert, Combinatorial evaluation of the host-guest chemistry of star-shaped block 

copolymers. J. Comb. Chem. 7, 356 (2005) 

D. Wouters, U.S. Schubert, Sequential oxidation and functionalization of nanostructures: the site-specific 

controlled assembly of different sized particles on a surface. J. Mater. Chem. 15, 2353 (2005) 

B.G.G. Lohmeijer, U.S. Schubert, The lego toolbox: supramolecular building blocks by nitroxide mediated 

controlled radical polymerization. J. Polym. Sci.: Part A: Polym. Chem. 43, 6331 (2005) 

V.N. Marin, Elisabeth Holder, M.M. Wienk, E. Tekin, D. Kozodaev, U.S. Schubert, Inkjet printing of 

electron donor/ acceptor blends: towards bulk heterojunction solar cells. Macromol. Rapid Commun. 26, 

319 (2005) 

H. Hofmeier, U.S. Schubert, Combination of different orthogonal supramolecular interactions in 

polymeric architectures. Chem. Commun. 2423 (2005) 

M.W.M. Fijten, R.M. Paulus, U.S. Schubert, Systematic parallel investigation of raft polymerizations for 

eight different (meth)acrylates: a basis for the designed synthesis of block and random copolymers. J. 

Polym. Sci.: Part A: Polym. Chem. 43, 3831 (2005) 

44


C. Guerrero-Sanchez, D. Wouters, C.-A. Fustin, J.-F. Gohy, B.G.G. Lohmeijer, U.S. Schubert, Structure 

property study of diblock copolymer micelles: core and corona radius with varying composition and degree 

of polymerization. Macromolecules 38, 10185 (2005) 

45


46

Nano-engineering / cNM Nanophotonic Devices 

Nanophotonic Devices M.K. Smit 

Nanotechnology, combined with photonics, is a field that will lead to radically new concepts in 

optical information processing, providing the next generation optical communication technology. 

The emerging of nanotechnology enables a spectacular reduction in size of photonic integrated 

circuits (PICs) through the increased control of size and shape of optical and opto-electronic 

structures. Also it enables new functionalities in these circuits. In particular it allows for the 

development of photonic crystals, structures in which mixing of optical modes and optical 

resonances plays a dominant role, and quantum dot or quantum wire devices, semiconductor 

devices in which the properties of opto-electronic materials can be manipulated by controlling the 

dimensions and positions of embedded quantum dots or wires on an atomic scale. The program 

focuses on extending existing expertise on ultracompact photonic devices towards nanophotonic 

devices in which the ultimate confinement of light in Photonic crystal structures will be combined 

with the ultimate confinement of electrons in Quantum Dots, in order to shift fundamental 

barriers in electro-optic interactions that exist in classical device structures. The research is done 

in cooperation with Physics of Semiconductor Nanostructures group. 


1. Photonic integrated circuits in III-V material. Integration of passive devices with 

semiconductor optical amplifiers, optical switches and modulators. Emphasis on 

reduction of device dimensions and operation speed. Requirements on control of device 

dimensions in nanometer range. 

2. Photonic crystal devices. Extremely compact wavelength selective devices like filters and 

demultiplexers. Microcavity lasers. 

3. Quantum-dot based electro-optical devices. Use of QD-layers in non-linear devices (photonic 

logic) and in lasers and optical amplifiers. 

Keywords 

Photonic integrated circuits, photonic integration, quantum dots, quantum wires, photonic 

crystals, photonic band gap, III-V-Semiconductors 



Senior staff 4.0 2 

PhD 2.0 1.6 

Post doc 



Prasanth, R.; Notzel, R.; Wolter, J.H.; Haverkort, J.E.M.; Deepthy, A.; Bogaart, E.W.; Tol, J.J.G.M. van der; 

Patent, E.; Zhao, G.; Gong, Q; Veldhoven, P.J.: All-optical switching due to state-filling in quantum dots. 

Appl. Phys. Lett., Vol 84, Nr 20, pp. 4059-4061, 2004. 

Hill, M.T.; Leijtens, X.J.M.; Khoe, G.D.; Smit, M.K.: Optimizing imbalance and loss in 2 x 2 3-dB 

multimode interference couplers via access waveguide width. J. Lightwave Technol. 21, nr. 10, 2003, 

47


pp. 2305-2313. 

Broeke, R G , Binsma, J.J.M. , Geemert, M. van , Heinrichsdorff, F , Dongen, T. van , Zantvoort, J.H.C. van, 

Leijtens, X.J.M. , Oei, Y.S. & Smit, M.K. All-optical wavelength converter with a monolithically integrated 

digitally tunable laser. proc. ECOC 2002 conference, Copenhagen, 8-12 September 2002, paper nr PD 3.2 

Besten, J.H. den , Broeke, R G , Geemert, M. van , Binsma, J.J.M. , Heinrichsdorff, F , Dongen, T. van , 

Vries, T.J. de , Bente, E.A.J.M. , Leijtens, X.J.M. & Smit, M.K. ;A compact digitally tunable seven-channel ring 

laser.IEEE Photonics Technology Letters, 14(6), 753-755, 2002 

C.G.P. Herben, D.H.P. Maat, X.J.M. Leijtens, M.R. Leys, Y.S. Oei and M.K. Smit Polarization Independent 

Dilated WDM Optical Cross–Connect on InP IEEE Photon.Technol.Lett., Vol. 11, No. 12, Dec. 1999, pp. 

1599–1601. 


The optical self-switching combiner, an application of nanophotonic material 

Quantum dots are the nanophotonic material par excellence. Having dimensions in the order of a 

few nanometers they provide a means to manipulate the electronic and optical properties of 

semiconductors. E.g., they show exciting non-linear behavior. A non-linear optical device has 

been realized recently with these QDs. The combining of optical signals is a basic function in 

optical fiber communication, which is usually performed with passive devices, so called 3dBcouplers, 

which have the fundamental property of radiating out half of the light power. This 

unwanted loss of 3dB can be avoided with optical switches, but this is not convenient, since then a 

complicated control and management system is required. A better solution is a self-switching 

device, in which the optical signals themselves set the transmission path, thus avoiding both the 3 

dB loss and the control system. This can be done with a non-linear optical effect. Together with 

the Semiconductor Physics group (HGF) we have developed such a combiner. It uses nanostructured 

optical material: quantum dots. The device and the optical switching curve are shown 

in figure 1. 

x/(1-x) coupler splitter 

QD 

QD 

Non 

Fig.1: Left: Self-switching combiner circuit. Right: Switching curve, Pin (horizontal axis) is the optical input 

power, the vertical axis shows the ratio between the transmission of a self-switching combiner and a passive 

3dB-coupler 

The combiner is an interferometer with an unequal power distribution over the branches. This 

results in unequal power dependent phase shifts between these branches, and hence in a 

switching effect. With respect to a 3dB coupler an improvement of 1.76 dB is found, reducing the 

loss to 1.24 dB. To put this in perspective: in a typical optical tree network up to 16 splitting stages 

can be required, so the improvement found results in a reduction of power budgets by 28 dB, 

implying a huge relaxation of transmitter and receiver requirements (and costs). 

48



Prof.dr.ir. M.K. Smit 

Meint Smit is the leader of the Opto-Electronic Devices group. He is the inventor of the Arrayed 

Waveguide Grating demultiplexers, which has found worldwide application. He has a broad 

experience with Photonic Integration of Semiconductor based devices, with emphasis on compact 

and fabrication-tolerant design and technology. He is author/co-author of more than 250 papers 

and 2 patents. 

Dr. J.J.G.M. van der Tol 

Jos van der Tol is associated professor in the OED group. His field of interest include photonic 

crystals, optical polarization manipulation and interferometric devices.He has a broad experience 

in the design and realization of integrated optical components on lithium niobate and indium 

phosphide. He has 26 patents to his name. 

Dr. F. Karouta 

Fouad Karouta is associated professor in the OED group. His field of interest includes the 

technology of III-V semiconductors including dry etching, PECVD of dielectrics. He has 1 patent 

to his name. 

Dr. Y.S. Oei 

Siang Oei is associated professor in the OED group. His field of interest includes all aspects of the 

technology of III-V semiconductors. He has developed the so-called descum-process for the 

etching of high quality waveguides on InP, which is the basis of all OED realizations. A recent 

activity is the development of a technology for photonic crystals. 

Selected publications 1999-2003 

1999 

C.G.P. Herben, X.J.M. Leijtens, P. Maat, H. Blok and M.K. Smit Crosstalk Performance of Integrated 

Optical Cross–Connects Journal of Lightwave Technology, Vol. 17, No. 7, July 1999, pp. 1126–1134. 

J. Stulemeijer, F.E. van Vliet, K.W. Benoist, D.H.P. Maat and M.K. Smit Compact Photonic Integrated 

Phase and Amplitude Controller for Phased–Array Antennas IEEE Photonics Technology Letters, Vol. 11, 

No. 1, Jan. 1999, pp. 122–124. 

J. Stulemeijer, A.F. Bakker, I. Moerman, F.H. Groen and M.K. Smit InP–Based Spotsize Converter for 

Integration with Switching Devices IEEE Photonics Technology Letters, Vol. 11, No. 1, Jan. 1999, pp. 81–83. 

H.G. Bukkems, C.G.P. Herben, M.K. Smit, F.H. Groen and I. Moerman Minimisation of the Loss of 

Intersecting Waveguides in InP Based Photonic Integrated Circuits IEEE Photon.Technol.Lett., Vol. 11, No. 

11, Nov. 1999, pp. 1420–1422. 

C.G.P. Herben, D.H.P. Maat, X.J.M. Leijtens, M.R. Leys, Y.S. Oei and M.K. Smit Polarization Independent 

Dilated WDM Optical Cross–Connect on InP IEEE Photon.Technol.Lett., Vol. 11, No. 12, Dec. 1999, pp. 

1599–1601. 

P.J. Harmsma, M.K. Smit, Y.S. Oei, M.R. Leys, C.A. Verschuren and H. Vonk Multi Wavelength Lasers 

Fabricated Using Selective Area Chemical Beam Epitaxy Proc. IPR, Santa Barbara, California, 1999, pp. 17– 

19. 

Y.C. Zhu, F.H. Groen, D.H.P. Maat, Y.S. Oei, J. Romijn and I. Moerman A Compact Phasar with Low 

Central Channel Loss Proc. ECIO’99, Torino, Italy, 13–16 April 1999, pp. 219–222. 

C.A. Verschuren, M.R. Leys, H. Vonk, J.H. Wolter, P.J. Harmsma and Y.S. Oei Butt–Coupling Loss of 0.1 

dB/Interface in InP/InGaAs Multi–Quantum–Well Waveguide–Waveguide Structures grown by Selective 

Area Chemical Beam Epitaxy Turkish Journal of Physics, Vol. 23, No. 24, 1999, pp. 657–664. 

49


H.G. Bukkems, J.E.M. Haverkort, M.R. Leys, N. Futakuchi, Y. Nakano, Y.S. Oei and M.K. Smit An 

InGaAsP/InGaAs Quantum Well Suitable for a Self Electro–Optic Effect Device Proc. IEEE/LEOS Benelux 

Chapter, Mons, Belgium, Nov. 1999, pp. 243–246. 

Buda, M.; Karouta, F.; Iordache, G.; Tan, H.H.; Jagadish, C.; Smalbrugge, E.; Roy, B.H. van; Vleuten, W.C. 

van der; Silov, A.Yu.: Quantum well intermixing in 980 nm laser structures using PECVD SiOxNy/SiOx 

layers. Proc. 4th Annual Symposium of the IEEE/LEOS Benelux Chapter, 1999, pp. 219-222. 

2000 

Thourhout, D. van; Hove, A. van; Caenegem, T. van; Moerman, I.; Daele, P. van; Baets, R.; Leijtens, X.J.M.; 

Smit, M.K.: Packaged hybrid integrated phased-array multi-wavelength laser. Electron. Lett. 36, nr. 5, 

2000, pp. 434-436. 

Verschaffelt, G.; Ryvkin, B.; Thienpont, H.; Acket, G.A.; Vleuten, W.C. van der; Creusen, M.P.; Smalbrugge, 

E.; Roer, T.G. van de; Karouta, F.; Strijbos, R.C.; Danckaert, J.; Veretennicoff, I.: Polarization stabilization 

in vertical-cavity surface-emitting lasers through asymmetric current injection. IEEE Photonics Technol. 

Lett. 12, 2000, pp. 945-947. 

Bukkems, H.G.; Oei, Y.S.; Richter, U.; Gruska, B.: Analysis of III-V layer stacks on InP substrates using 

spectroscopic ellipsometry in the NIR spectral range. Thin Solid Films 364, 2000, pp. 165-170. 

Harmsma, P.J. Integration of semiconductor optical amplifiers in wavelength division multiplexing 

photonic integrated circuits PhD Thesis, Delft University of Technology, ISBN 90-9014315-7, December 

2000 

Extremely compact WDM cross connect on InP. Proc. 5th Annual Symposium of the IEEE/LEOS Benelux 

Chapter, 30 October 2000, ISBN 90-9014260-6, ed. X.J.M. Leijtens; J.H. den Besten; Delft Univ. of 

Technology, 2000, pp. 17-20. 

Smit, M.K.; Herben, C.G.P.: Photonic integrated circuits for WDM applications. Proc. Optoelectronics and 

Communications Conference, 11-14 July 2000, pp. 150-151. 

Herben, C.G.P. Compact integrated cross connects for wavelength-division multiplexing networks PhD 

Thesis, Delft University of Technology, ISBN 90-9014303-3, December 2000 

Thourhout, D. van; Hove, A. van; Caenegem, T. van; Vandeputte, K.; Vandaele, P.; Moerman, I.; Leijtens, 

X.J.M.; Smit, M.K.; Baets, R.: Phased-array multiwavelength laser using hybridly integrated PICs. Proc. 

ECTC 2000, 21-24 May 2000, pp. 1266-1271. 

Harmsma, P.J.; Vonk, H.; Leys, M.R.; Oei, Y.S.: Effect of butt joint reflections on the performance of 

extended cavity lasers and phased array multi-wavelength lasers. Proc. 5th Ann. Symp. IEEE/LEOS Benelux 

Chapter, 30 Oct. 2000, ISBN 90-9014260-6, 2000, pp. 123-126. 

Stulemeijer, J.; Dijk, R. van; Vliet, F.E. van; Maat, D.H.P.; Smit, M.K.: Photonic Chip for Steering a Four 

Element Phased Array Antenna. Proceedings of Microwave Photonics Conference, 11-13 September 2000, 

pp. 20-22. 

2001 

Smit, M.K.; Koonen, A.M.J.; Herrmann, H.; Sohler, W.: PHASAR-based devices and Integrated acoustooptical 

devices in LiNbO3. Fibre Optic Communication Devices, ISBN 3-540-66977-9, ed. N. Grote; H. 

Venghaus; Springer Verlag, 2001, pp. 281-312. 

Augustin, L.M.; Strijbos, R.C.; Smalbrugge, E.; Choquette, K.; Verschaffelt, G.; Geluk, E.J.; Karouta, F.; 

Roer, T.G. van de: Processing of intra-cavity VCSELs in structures with doped DBRs. Proc. IEEE/LEOS 

Annual Symposium, 3 December 2001, ISBN 90-5487247-0, ed. H. Thienpont; F. Berghmans; J. 

Danckaert; L. Desmet; VUB, Brussel, 2001, pp. 113-117. 

Besten, J.H. den; Broeke, R G; Geemert, M. van; Binsma, J.J.M.; Vries, T.J. de; Leijtens, X.J.M.; Smit, M.K.: 

A compact 4-channel multi-wavelength ringlaser. proc. 6th Annual Symposium of the IEEE/LEOS Benelux 

Chapter, 3-3 December 2001, ISBN 90-5487247-0, ed. Hugo Thienpont; Francis Berghmans; Jan 

Danckaert; Lieven Desmet; Vrije univ. Brussel en IEEE/LEOS, Brussels, Belgium, 2001, pp. 33-36. 

50


Besten, J.H. den; Broeke, R G; Geemert, M. van; Binsma, J.J.M.; Vries, T.J. de; Leijtens, X.J.M.; Smit, M.K.: 

A dual-phasar multi-wavelength ringlaser. Proc. IEEE/LEOS Annual Symposium, 3 December 2001, ISBN 

90-5487247-0, ed. H. Thienpont; F. Berghmans; J. Danckaert; L. Desmet; VUB, Brussel, 2001, pp. 189-103. 

Binsma, J.J.M.; Geemert, M. van; Broeke, R G; Bente, E.A.J.M.; Smit, M.K.: MOVPE waveguide regrowth 

in InGaAs/InP with extremely low butt-joint loss. Proc. IEEE/LEOS Annual Symposium, 3 December 

2001, ISBN 90-5487247-0, ed. H. Thienpont; F. Berghmans; J. Danckaert; L. Desmet; VUB, Brussel, 2001, 

pp. 245-249. 

Broeke, R G; Binsma, J.J.M.; Geemert, M. van; Leijtens, X.J.M.; Vries, T.J. de; Smit, M.K.: A MOVPE 

grown phaser-based multi-wavelength laser with suppression of unwanted orders. proc. 6th Annual 

Symposium of the IEEE/LEOS Benelux Chapter, 3-3 December 2001, ISBN 90-5487247-0, Brussels, 

Belgium, 2001, pp. 201-204. 

Broeke, R G; Binsma, J.J.M.; Geemert, M. van; Smit, M.K.: Monolithical integration of semiconductor 

optical amplifiers and passive modefilters for low facet reflectivity. Proc. IEEE/LEOS Annual Symposium, 3 

December 2001, ISBN 90-5487247-0, ed. H. Thienpont; F. Berghmans; J. Danckaert; L. Desmet; VUB, 

Brussel, 2001, pp. 57-61. 

Karouta, F.; Jacobs, B.; Kramer, M.C.J.C.M.: Role of Fluorine in a Chlorine-Based Reactive Ion Etching of 

Semiconductors. Proc. Conference on Semiconductors and Integrated Opto-Electronics, 9-11 April 2001; 

University of Wales, Cardiff, 2001. 

Zhu, Y.; Groen, F.H.; Leijtens, X.J.M.; Tol, J.J.G.M. van der: Single-section polarisation converter on 

InP/InGaAsP using asymmetrical waveguides. Proc. IEEE/LEOS Annual Symposium, 3 December 2001, 

ISBN 90-5487247-0, ed. H. Thienpont; F. Berghmans; J. Danckaert; L. Desmet; VUB, Brussel, 2001, 

pp. 209-213. 

2002 

Besten, J.H. den , Broeke, R G , Geemert, M. van , Binsma, J.J.M. , Heinrichsdorff, F , Dongen, T. van , 

Vries, T.J. de , Bente, E.A.J.M. , Leijtens, X.J.M. & Smit, M.K. A compact digitally tunable seven-channel 

ring laser. IEEE Photonics Technology Letters, 14(6), 753-755. 

Besten, J.H. den , Dessens, M.P. , Herben, C.G.P. , Leijtens, X.J.M. , Groen, F.H. , Leys, M.R. & Smit, M.K. 

Low-loss, compact and polarization independent PHASAR demultiplexer fabricated by using a double-etch 

process. IEEE Photonics Technology Letters, 14, 62-64. 

Stulemeijer, J. Integrated optics for microwave phased-array antennas. TU Delft (11-02-2002). 149 pp. 

promot.: prof.dr.ir. M. K. Smit & prof.dr.ir. H. Blok. 

Besten, J.H., Broeke, R.G., Geemert, M. van, Binsma, J.J.M., Heinrichsdorff, F., Dongen, T. van, Bente, 

E.A.J.M., Leijtens, X.J.M., Smit, M.K An Integrated Coupled-Cavity 16-Wavelength Digitally Tunable Laser 

IEEE Photon. Technol. Lett., vol 14, no. 12 December 2002, pp. 1653-1655 

Besten, J.H. den , Broeke, R G , Vries, A. de , Leijtens, X.J.M. , Smit, M.K. , Geemert, M. van & Binsma, 

J.J.M. (2002). A dual-phasar multi-wavelength ringlaser. Proceedings OFC 2002 Anaheim, pp. 203-205. 


Leijtens, X.J.M. , Oei, Y.S. & Smit, M.K. All-optical wavelength converter with a monolithically integrated 

digitally tunable laser. proc. ECOC 2002 conference, Copenhagen, 8-12 September 2002, paper nr PD 3.2 


Tangdiongga, , Waardt, H. de , Leijtens, X.J.M. , Oei, Y.S. & Smit, M.K. An all-optical wavelength converter 

in a layer-stack suitable for compact photonic integration. proc. IPR'02 Conference, Vancouver, Canada. 

pp. 1-3 

I.M. Augustin, E. Smalbrugge, F. Karouta, K. D. Choquette, G. Verschaffelt, R. C. Strijbos, E.-J. Geluk, T. 

G. v.d. Roer, H. Thienpont Controlled Polarization Switching in VCSELs by means of Asymmetric Current 

Injection 7 th IEEE/LEOS Benelux Annual Meeting, Amsterdam, NL, December 2002, pp. 63-66 

51


U.Khalique , Y.C. Zhu , J.J.G.M. van der Tol , F.Karouta , E.J. Geluk , T. J. Eijkemans , J.E.M. Haverkort , 

H.H. Tan , C. Jagadish . Realization of POLIS components: Waveguides, LEDs and Detectors 7 th 

IEEE/LEOS Benelux Annual Meeting, Amsterdam, NL, December 2002, pp. 20-23 

E.A. Patent , J.J.G.M. van der Tol , R.G. Broeke ,J.J.M. Binsma . Semiconductor Optical Amplifiers in a 

non-linear Mach-Zehnder Interferometer. 7 th IEEE/LEOS Benelux Annual Meeting, Amsterdam, NL, 

December 2002, pp. 222-225 

2003 

Besten, J.H. den; Broeke, R.G.; Geemert, M. van; Binsma, J.J.M.; Heinrichsdorff, F.; Dongen, T. van; Bente, 

E.A.J.M.; Leijtens, X.J.M.; Smit, M.K.: An integrated 4x4-channel multi-wavelength laser on InP. IEEE 

Photonics Technol. Lett. 15, nr. 3, 2003, pp. 368-370. 

Prasanth, R.; Notzel, R.; Wolter, J.H.; Haverkort, J.E.M.; Deepthy, A.; Bogaart, E.W.; Tol, J.J.G.M. van der; 

Patent, E.; Zhao, G.; Gong, Q; Veldhoven, P.J.: All-optical switching due to state-filling in quantum dots. 

Appl. Phys. Lett., Vol 84, Nr 20, pp. 4059-4061, 2004. 

Hill, M.T.; Leijtens, X.J.M.; Khoe, G.D.; Smit, M.K.: Optimizing imbalance and loss in 2 x 2 3-dB 

multimode interference couplers via access waveguide width. J. Lightwave Technol. 21, nr. 10, 2003, 

pp. 2305-2313. 

Zhao, G.; Patent, E.; Tol, J.J.G.M. van der: Modeling of optical nonlinearities based on engineering the 

semiconductor band. Materials Science in Semiconductor Processing 6, 2003, pp. 153-158. 

Pascher, W.; Besten, J.H. den; Caprioli, D.; Leijtens, X.J.M.; Smit, M.K.; Dijk, R. van: Modelling and design 

of a travelling-wave electro-optic modulator on InP. Opt. Quantum Electron. 35, 2003, pp. 453-464. 

Groen, F.H.; Zhu, Y.; Tol, J.J.G.M. van der: Compact polarization converter on InP/InPGaAs using an 

asymmetrical waveguide. Proc. ECIO'03. 1, 2-4 April 2003, ISBN 80-01-02729-5, pp. 141-144. 

Smit, M.K.: Integrated devices employing SOAs. Technical Digest of the OAA 2003, 6-9 July 2003; OSA, 

Otaru, Japan, 2003, pp. 34-36. 

Hanfoug, R; Tol, J.J.G.M. van der; Augustin, L M; Smit, M.K.: Wavelength conversion with polarisation 

labelling for rejection and isolation of signals (POLARIS). Proc. 11th European Conference on Integrated 

Optics, ECIO'03. 1, 2-4 April 2003, ISBN 80-01-02729-5, ed. Jiri Ctyroky, Prague, Czech Republic, 2003, 

pp. 105-108. 

Barbarin, Y; Leijtens, X.J.M.; Bente, E.A.J.M.; Kooiman, J.; Smit, M.K.: Extremely small AWG demultiplexer 

fabricated on InP by using a double-etch process. proc. IEEE/LEOS Benelux Annual Symposium 2003, 

Enschede, The Netherlands, 20-21 November 2003; IEEE, Enschede, The Netherlands, 2003, pp. 61-64. 

Haverkort, J.E.M.; Notzel, R.; Wolter, J.H.; Prasanth, R.; Deepthy, A.; Bogaart, E.W.; Tol, J.J.G.M. van der; 

Patent, E.; Zhao, G.; Gong, Q; Veldhoven, P.J. van: Wavelength insensitive all-optical switching in quantum 

dots. proc. IEEE/LEOS Benelux Annual Symposium 2003, Enschede, The Netherlands, 20-21 November 

2003; IEEE, Enschede, The Netherlands, 2003, pp. 193-196. 

52

Nano-engineering / cNM Direct-Write Atom Lithography 

Direct-Write Atom Lithography H.C.W. Beijerinck / K.A.H. van Leeuwen 

Direct-write atom lithography is a technique in which nano-structures are directly deposited from 

an atomic beam that is structured by light fields. In the simplest version, a one-dimensional 

standing light wave induces a spatially modulated dipole potential that acts as a lens array for the 

atoms, resulting in narrow structures. This has proven to be a powerful tool for the production of 

periodic nano-structures. It has been applied to Na, Cr and Al, and very recently to Fe by our 

group and by the group of Rasing in Nijmegen, thereby adding the first ferromagnetic element to 

the list. The simple, additive character of the technique is an advantage. The idea of an MBE setup 

that directly produces devices is very appealing. In addition to the production and study of 

periodic ferromagnetic nano-structures with Fe, we are pursuing novel approaches to lift the 

current restriction of the technique to simple periodic structures and only a few materials, and to 

increase the writing speed drastically. Furthermore, we are working on the production of fully 

novel structures by structured doping, i.e., achieving materials with their composition varied on the 

nanometer scale by simultaneous deposition of different species. 


1. Periodic nano-structures of ferromagnetic materials (Fe). 

2. Complicated, non-periodic nano-structures by applying holographically produced light fields 

for beam structuring which replace the usual simple geometry of a standing light wave. 

3. Direct-write of structures/connects with a 'nano-beam' or 'nano-pencil’ obtained by 

compression of an atomic beam in a single focused sub-100 nm size beam, which can be 

used in the same way as focused ion beam writer. Due to the absence of space charge 

problems, writing speed can be at least three orders of magnitude higher. 

4. Development of high-intensity metal beam sources. This will allow atom lithography to be 

applied to a much larger variety of deposition materials. 

5. Structured doping, i.e., the production of materials like Fe-Ni with nanostructured Fe 

concentration. 

Keywords 

Direct-write lithography, nanostructures, interference, holography. 

53





PhD 2.0 1.6 

Post doc 


o 


A.E.A. Koolen, G.T. Jansen, K.F.E.M. Domen, H.C.W. Beijerinck, K.A.H. van Leeuwen, Large 

angle, adjustable coherent atomic beam splitter, Phys. Rev. A 65, R041601, (2002) 

R.C.M. Bosch, H.C.W. Beijerinck, P. van der Straten, K.A.H. van Leeuwen, Supersonic Fe beam 

source for chromatic abberation-free laser focusing of atoms, Eur. Phys. J. Appl. Phys. 18, 221-227, 

(2002) 

E. te Sligte, R.C.M. Bosch, B. Smeets, P. van der Straten, H.C.W. Beijerinck, K.A.H. van Leeuwen, 

Magnetic nanodots from atomic Fe: can it be done?, Proc. Nat. Acad. Sci. 99, 6509-6513, (2002) 

E. te Sligte, K.M.R. van der Stam, B. Smeets, P. van der Straten, R.E. Scholten, H.C.W. Beijerinck, 

K.A.H. van Leeuwen, Barrier-limited surface diffusion in atom lithography, J. Appl. Phys. 95, 1749- 

1755 (2004) 

E. te Sligte, B. Smeets, K.M.R. van der Stam, R.W. Herfst, P. van der Straten, H.C.W. Beijerinck, 

K.A.H. Van Leeuwen, Atom lithography of Fe, Appl. Phys. Lett. 85, 4493-4495 (2004) 

o 

54



Figure 1: Basic principle of 

direct-write atom 

lithography 

We have succeeded in producing the first Fe nanostructures using the directwrite 

atom lithography technique. In the first attempts, using a onedimensional 

standing light wave of 372 nm wave length to focus Fe atoms in 

a collimated beam, an array of lines with 186 nm spacing and a width of 55 

nm and a height of 0.5 nm has been produced in a 1 by 1 mm area. These 

results have been published in Applied Physics Letters and have received 

attention in, e.g., Physics Today. Since then, we have drastically increased the 

height of the observed structures and reduced the width. 

Most importantly, we have achieved this while eliminating the complicated, 

bottle-neck step of atomic beam collimation by laser cooling, which has thus 

far been used in every atom lithography experiment. As a result, the 

technique can now be extended to virtually any atomic species, while 

previously having been restricted to just a very few elements. This can be 

considered as a true breakthrough in the atom lithography field. 

Presently, we are working to exploit our “no-laser-cooling” lithography 

technique to the production of nanostructured Fe-Ni alloy samples using 

simultaneous deposition of Fe (structured) and Ni (unstructured). This application of structured doping 

should result in a superlattice of alternating hard- and soft ferromagnetic nanolines. The effort is 

undertaken in close collaboration with the FNA group. 


Prof. dr. H.C.W. Beijerinck 

AQT group leader: Thermal and supersonic beam sources, surface reactions, atomic collisions, 

ultracold atoms 

Prof. dr. K.A.H. van Leeuwen 

AQT nanostructure research leader: Atom optics, atom lithography, (quantum) optics, 

nanostructures 

Dr. ir. E.J.D. Vredenbregt 

AQT senior scientist: Bright atomic beams, ultracold gases, atom-light interactions 

Dr. S.J.J.M.F. Kokkelmans 

VIDI fellow: Theory of ultracold gases 

Figure 2: AFM scan of Fe nanostructure 

55



2001 

J. Schuster, A. Marte, S. Amtage, B. Sang, G. Rempe, H.C.W. Beijerinck, Avalanches in a Bose-Einstein 

condensate, Phys. Rev. Lett. 87, 170404, (2001) 

2002 

S.J.M. Kuppens, J.G.C. Tempelaars, V.P. Mogendorff, B.J. Claessens, H.C.W. Beijerinck, E.J.D. 

Vredenbregt, Approaching Bose-Einstein condensation of metastable neon: over 10 9 trapped atoms, Phys. Rev. A 

65, 023410, (2002) 

J.G.C. Tempelaars, R.J.W. Stas, P.G.M. Sebel, H.C.W. Beijerinck, E.J.D. Vredenbregt, An intense and cold 

beam of metastable Ne(3s) 3 P2 atoms, Eur. Phys. J. D 18, 113-121, (2002) 

A.E.A. Koolen, G.T. Jansen, K.F.E.M. Domen, H.C.W. Beijerinck, K.A.H. van Leeuwen, Large angle, 

adjustable coherent atomic beam splitter, Phys. Rev. A 65, R041601, (2002) 

R.C.M. Bosch, H.C.W. Beijerinck, P. van der Straten, K.A.H. van Leeuwen, Supersonic Fe beam source for 

chromatic abberation-free laser focusing of atoms, Eur. Phys. J. Appl. Phys. 18, 221-227, (2002) 

E. te Sligte, R.C.M. Bosch, B. Smeets, P. van der Straten, H.C.W. Beijerinck, K.A.H. van Leeuwen, Magnetic 

nanodots from atomic Fe: can it be done?, Proc. Nat. Acad. Sci. 99, 6509-6513, (2002) 

J. Ye, S.T. Cundiff, S. Foreman, T.M. Fortier, J.L. Hall, K.W. Holman, D.J. Jones, J.D. Jost, H.C. Kapteyn, 

K.A.H. van Leeuwen, L.S. Ma, M.M. Murnane, J.L. Peng, R.K. Shelton, Phase-coherent synthesis of optical 

frequencies and waveforms, Appl. Phys. B 74: S27-S34 (2002) 

2003 

E.J.D. Vredenbregt, K.A.H. van Leeuwen, Laser cooling and trapping visualized, Am. J. Phys. 71, 760-765, 

(2003) 

E. te Sligte, B. Smeets, K.M.R. van der Stam, L.P. Maguire, R.E. Scholten, K.A.H. van Leeuwen, Progress 

towards atom lithography on iron, Microelectronic Engineering 67-68, 664-669, (2003) 

B. Smeets, R.C.M. Bosch, P. van der Straten, E. te Sligte, R.E. Scholten, H.C.W. Beijerinck, K.A.H. van 

Leeuwen, Laser frequency stabilization using an Fe-Ar hollow cathode discharge cell, Appl. Phys. B 6, 815-819, 

(2003) 

S.J.H. Petra, K.A.H. van Leeuwen, L. Feenstra, W. Hogervorst, W. Vassen, Numerical simulations on the 

motion of atoms travelling through a standing-wave light field, Eur. Phys. J.D. 27, 83-91, (2003) 

2004 

S.J.H. Petra, K.A.H. Van Leeuwen, L. Feenstra, W. Hogervorst, W. Vassen, Atom lithography with twodimensional 

light masks, Appl. Phys. B 79, 279-283 (2004) 

M.H.L. Van der Velden, H. Batelaan, E. te Sligte, H.C.W. Beijerinck, E.J.D. Vredenbregt, Low-pressure source 

of slow metastable rare gas atoms, Rev. Sci. Instr. 75, 1073-1077 (2004) 

E. te Sligte, K.M.R. van der Stam, B. Smeets, P. van der Straten, R.E. Scholten, H.C.W. Beijerinck, K.A.H. 

van Leeuwen, Barrier-limited surface diffusion in atom lithography, J. Appl. Phys. 95, 1749-1755 (2004) 

E. te Sligte, B. Smeets, K.M.R. van der Stam, R.W. Herfst, P. van der Straten, H.C.W. Beijerinck, K.A.H. 

Van Leeuwen, Atom lithography of Fe, Appl. Phys. Lett. 85, 4493-4495 (2004) 


B. Smeets, R.W. Herfst, E. te Sligte, P. van der Straten, H.C.W. Beijerinck, K.A.H. van Leeuwen, 

Laser-cooling simulation based on the semiclassical approach, J. Opt. Soc. Am. B 22, 2372-2377 (2005) 

B. Smeets, R.W. Herfst, L.P. Maguire, E. te Sligte, P. van der Straten, H.C.W. Beijerinck, K.A.H. van 

Leeuwen, Laser collimation of an Fe atomic beam on a leaky transition, Appl. Phys. B 80, 833-839 (2005) 

56


R. Stützle, M.C. Goebel, T. Hörner, E. Kierig, I. Mourachko, M.K., Oberthaler, M.A. Efremov, M.A., 

Fedorov, V.P. Yakovlev, K.A.H. van Leeuwen, Schleich, W.P., Observation of nonspreading wave packets in an 

imaginary potential, Phys. Rev. Lett. 95, 110405 (2005) 

A.A.E. Stevens, H.C.W.Beijerinck, Surface roughness in XeF2 etching of a-Si/c-Si(100), J. Vac. Sci. Techn. A 

23, 126-136 (2005) 

57

Nano-engineering / cNM Micron and Submicron Mechanics 

58


Micron and Submicron Mechanics M.G.D. Geers 

The mechanics at the scale of micro-systems is substantially different from the one that is 

commonly observed on a macroscopic engineering scale. Differences between standard 

continuum mechanics predictions and reality may be as large as a factor of 4x, clearly illustrating 

the need for a fundamental micromechanical and theoretical basis if a proper understanding of 

the mechanical behavior of micro-systems down to the nano-scale is to be developed. Apart from 

this intrinsic difference in the mechanics at the macro and the (sub-)micron scale, care has to be 

taken to incorporate the heterogeneous (multi-phase, anisotropic) character of the material. The 

size of the individual phases is in general no longer negligible with respect to the geometrical 

dimensions of the micro-systems. Advanced micromechanical and multi-scale theories need to be 

used to address this, e.g. crystal plasticity, continuum dislocation theories, computational 

homogenization frameworks. Furthermore, interactions with small-scale deformation 

mechanisms are expected, possibly influencing various microstructural effects. 


1. Size effects. Fundamentals of size effects in micro-systems and experimental assessment of 

size effects triggered by gradients (use of ESEM, SEM, OIM, nano-indentation, microtensile 

stages, deformation imaging techniques). 

2. Mechanics of micro-components. Experimental assessment of the mechanics of microcomponents 

and MEMS through surface effects triggered by thin films (oxide layers, hard 

coatings). 

3. Higher-order theories. Higher-order theories, incorporating gradients of field variables and 

strongly nonlocal continuum mechanics for the analysis of micro-systems: modeling 

surface and interface effects in micro-devices with enhanced continua and/or small-scale 

deformation theories. 

4. Small metallic devices. Micro-mechanics of small metallic devices on the basis of enhanced 

crystal plasticity modeling, i.e. where the grain size is intrinsically large with respect to the 

micro-system, supported experimentally. 

5. Multi-scale mechanics. Multi-scale computational homogenization modeling of small-scale 

deformation mechanisms towards the mechanical behavior of micro-systems. 

6. Damage mechanics. Damage mechanics of microsystems emerging from the submicron 

dimensions through microstructure evolution, self-organisation and degradation. 

Keywords 

Micromechanics, size effects, higher-order continua, multi-scale mechanics, crystal plasticity, 

dislocation mechanics, constrained micro-systems, damage mechanics 




PhD 12.0 9.6 

Post doc 3 3 


This research group participates for 25% in the TU/e focus area Nano-engineering, i.e. the 

research contribution to Nano-engineering is 3.8 fte. 

59



R.A.B. Engelen, N.A. Fleck, R.H.J. Peerlings, M.G.D. Geers, An evaluation of higher-order 

plasticity theories for predicting size effects and localisation, Int. J. Solids Structures, 43(7-8), 

1857-1877, (2006) 

L.P. Evers, W.A.M. Brekelmans, M.G.D. Geers, Non-local crystal plasticity model with intrinsic 

SSD and GND effects, Journal of the Mechanics and Physics of Solids, 52(10), 2379-2401, (2004) 

R.L.J.M. Ubachs, P.J.G. Schreurs, M.G.D. Geers, A nonlocal diffuse interface model for 

microstructure evolution of tin-lead solder, Journal of the Mechanics and Physics of Solids, 52(8), 

1763-1792, (2004) 

J.A.W. van Dommelen, D.M. Parks, M.C. Boyce, W.A.M. Brekelmans, F.P.T. Baaijens, 

Micromechanical modeling of the elasto-viscoplastic behavior of semi-crystalline polymers, 

Journal of the Mechanics and Physics of Solids, 51, 519-541, (2003) 

V.G. Kouznetsova, M.G.D. Geers, W.A.M. Brekelmans, Multi-scale constitutive modelling of 

heterogeneous materials with a gradient-enhanced computational homogenization scheme, 

International Journal for Numerical Methods in Engineering, 54, 1235-1260, (2002) 

Research highlights 

Strain gradient crystal 

plasticity: A strain 

gradient crystal plasticity 

model has been 

developed recently, 

based on a physical and 

geometrical description 

of continuum dislocation 

fields in the crystal 

lattice. Geometrically 

necessary dislocations, 

which accommodate lattice curvature, that are typically relevant upon miniaturization, are 

explicitly accounted for. It is shown that this approach captures intrinsic scale size effects, as they 

occur upon changing specimen dimensions and or 

grain size. The illustration in figure 1 show the 

developed geometrically necessary dislocation (GND) 

fields in the grains as a function of the sample size. 

Clearly, larger gradients lead to large GND densities and 

hence to a increase in strength of the microstructure. 

Multi-scale computational homogenization: A multi-scale 

computational homogenization scheme has been 

developed that is capable of upscaling small-scale 

mechanics at the level of a microstructure or below to 

the engineering level. The proposed methodology allows 

to account for the (possibly evolving) size, shape, 

physical properties and spatial distribution of the 

microstructural constituents. An extended novel secondorder 

scheme has been proposed, based on a proper 

incorporation of the macroscopic gradient of the 

deformation gradient tensor and the associated higherorder 

stress measure into a multi-scale framework. This 

(a) L = 1.0 mm (b) L = 10 mm 

Distribution of the GND density measure for two sample lengths at an equivalent strain 

of ε = 0.01. 

60 

Shear patterning in a constrained elasto-plastic 

thin layer under shear, illustrating the 

boundary layer effects and the influence of the 

size of the representative volume element of 

the voided underlying microstructure.


allows describing certain phenomena that cannot be addressed by the classical (first-order) 

computational homogenization scheme, such as (geometrical) size effects, macroscopic 

localization and surface or boundary layer effects. 


Prof.dr.ir. M.G.D. Geers 

Full professor, heading the chair mechanics of materials in the Mechanical Engineering 

Department, with a particular emphasis on the mechanics at and across different length scales. 

Research emphasis: damage mechanics, micromechanics (scale size effects), multi-scale 

mechanics, generalized continua, crystal plasticity, phase transformations, dislocation 

substructuring, mechanics in micro-electronics (e.g. solder interconnects, flexible displays), metal 

forming (polymer coated steel). 

Dr.ir. W.A.M. Brekelmans 

Associate professor in the Department of Mechanical Engineering. Is involved in the area of the 

analytical description of the mechanical behavior of solids (constitutive formulation) (1) according 

to the classical phenomenological approach (elasticity, elastoplasticity, visco-elastoplasticity) and 

(2) more sophisticated, based on the micro-structure of materials (crystal plasticity), and the 

incorporation of the material models in numerical (finite element method) codes. Special 

attention is given to the relation between microscopical features and macroscopical response 

(homogenization). 

Dr.ir. R.H.J. Peerlings 

Assistant Professor in the Department of Mechanical Engineering. His research interests include 

the computational modelling of material damage and failure at spatial scales ranging from 

nanometres to millimetres. In particular, theories and numerical methods are developed which 

link these different scales and which thus allow to predict macroscopic failure based on 

understanding of the underlying, small-scale physical phenomena. 

Dr.ir. P.J.G. Schreurs 

Associate professor in the Department of Mechanical Engineering. Research emphasis: 

micromechanics, mechanics in micro-electronics (solder interconnects), mechanics of polymermetal 

laminates. 

Dr.ir. J.P.M. Hoefnagels 

Assistant professor in the Department of Mechanical Engineering, with an education in the 

physics department of the TU/e. Research emphasis: experimental multi-scale mechanics, 

including microscopy (ESEM, HR-SEM/OIM, optical, AFM), small scale experimental mechanics, 

thin film mechanics, nano-indentation, etc. 


2001 

L.P. Evers, D.M. Parks, W.A.M. Brekelmans, M.G.D. Geers, Enhanced modeling of hardening in crystal 

plasticity for FCC metals, Journal de Physique IV, 11, 179-186, (2001) 

M.G.D. Geers, V.G. Kouznetsova, W.A.M. Brekelmans, Gradient-enhanced computational homogenization 

for the micro-macro scale transition, Journal de Physique IV, 11, 145-152, (2001) 

V.G. Kouznetsova, W.A.M. Brekelmans, F.P.T. Baaijens, An approach to micro-macro modeling of 

heterogeneous materials, Comp. Mech., 27, 37-48, (2001) 

D.A. Taminiau, J.H. Dautzenberg, How to Understand Friction and Wear in Mechanical Working 

Processes, IJFP, 4(1-2), 9-23, (2001) 

61


W.P. Vellinga, C.P. Hendriks, Sliding friction dynamics of hard single asperities on soft substrates, Phys. 

Rev. E, 63, 066121-1 - 066121-14, (2001) 

M.G.D. Geers, R.A.B. Engelen, R.L.J.M. Ubachs, On the numerical modelling of ductile damage with an 

implicit gradient-enahced formulation, Revue Europ. des El. Finis, 10(2-3-4), 173-192, (2001) 

R.H.J. Peerlings, W.A.M. Brekelmans, R. de Borst, M.G.D. Geers, Mathematical and numerical aspects of 

an elasticity-based local approach to fracture, Revue Europ. des El. Finis, 10, 209-226, (2001) 

R.H.J. Peerlings, M.G.D. Geers, R. de Borst, W.A.M. Brekelmans, A critical comparison of nonlocal and 

gradient-enhanced softening continua, Int. J. Solids Structures, 38, 7723-7746, (2001) 

R.H.J. Peerlings, N.A. Fleck, Numerical analysis of strain gradient effects in periodic media, Journal de 

Physique IV, 11, 153-160, (2001) 

M.G.D. Geers, V.G. Kouznetsova, W.A.M. Brekelmans, Micro-macro scale transitions for engineering materials 

in the presence of size effects., Proceedings of the International Conference on Trends in Computational 

Structural Mechanics, Lake Constance, Austria, 118-127 (2001) 

2002 

L.P. Evers, D.M. Parks, W.A.M. Brekelmans, M.G.D. Geers, Crystal plasticity model with enhanced 

hardening by geometrically necessary dislocation accumulation, J. Mech. Phys. Solids, 50(II), 2403-2424, 

(2002) 

V.G. Kouznetsova, M.G.D. Geers, W.A.M. Brekelmans, Multi-scale constitutive modelling of heterogeneous 

materials with a gradient-enhanced computational homogenization scheme, Int. J. Numer. Meth. Engng, 

54, 1235-1260, (2002) 

K.M. Mussert, W.P. Vellinga, A Bakker, van der Zwaag, A Nano-indentation Study on the Mechanical 

Behaviour of the Matrix material in an AA6061-Al2O3 MMC, J. Mat. Sci., 37(4), 789-794, (2002) 

W.P. Vellinga, R. Rastogi, H.E.H. Meijer, Microscopic phenomenology of plastic deformation in polymermetal 

laminates., Mat. Res. Soc. Symp. Proc., 695, 21-26, (2002) 

D.W.A. Brands, P.H.M. Bovendeerd, J.S.H.M. Wismans, On the potential importance of non-linear 

viscoelastic material modelling for numerical prediction of brain tissue response: test and application, 

Stapp Car Crash Journal, 46(1), 103-121, (2002) 

R.H.J. Peerlings, R. de Borst, W.A.M. Brekelmans, M.G.D. Geers, Localisation issues in local and nonlocal 

continuum approaches to fracture, Eur. J. Mech. A/Solids, 21, 175-189, (2002) 

B.J.E. van Rens, W.A.M. Brekelmans, F.P.T. Baaijens, Modeling friction near sharp edges using a Eulerian 

reference frame: appliction to aluminium extrusion, Int. J. Numer. Meth. Engng, 54, 453-471, (2002) 

J.Z. Zhang, D.H. van Campen, G.Q. Zhang, V.P. Bouwman, Stability and bifurcation of doubly curved 

shallow panels under quasi-static uniform load, Int. J. Non-Linear Mech., 38(4), pp, (2002) 

L.P. Evers, W.A.M. Brekelmans, M.G.D. Geers, Different types of dislocation densities in a crystal plasticity 

model for FCC models, Proceedings of WCCM5, online available, Austria (2002) 

R.L.J.M. Ubachs, P.J.G. Schreurs, M.G.D. Geers, Microstructural evolution of solder joints subjected to 

thermomechanical loading, Proceedings of WCCM5, online available, Austria (2002) 

2003 

J.A.W. van Dommelen, D.M. Parks, M.C. Boyce, W.A.M. Brekelmans, F.P.T. Baaijens, Micromechanical 

modeling of the elasto-viscoplastic bahavior of semi-crystalline polymers, J. Mech. Phys. Solids, 51, 519-541, 

(2003) 

62


J.A.W. van Dommelen, W.A.M. Brekelmans, F.P.T. Baaijens, Micromechanical modeling of particletoughening 

of polymers by locally induced anisotropy, Mech. Mat., 35(9), 845-863, (2003) 

J.A.W. van Dommelen, W.A.M. Brekelmans, F.P.T. Baaijens, A numerical investigation of the potential of 

rubber and mineral particles for toughening of semicrystalline polymers, Comp. Mat. Sci., 27, 480-492, 

(2003) 

J.A.W. van Dommelen, D.M. Parks, M.C. Boyce, W.A.M. Brekelmans, F.P.T. Baaijens, Micromechanical 

modeling of intraspherulitic deformation of semicrystalline polymers, Polymer, 44, 6089-6101, (2003) 

J.A.W. van Dommelen, W.A.M. Brekelmans, F.P.T. Baaijens, Multiscale modeling of particle-modified 

polyethylene, J. Mat. Sci., 38, 4393-4405, (2003) 

W.D. van Driel, G.Q. Zhang, J.H.J. Janssen, Response surface modeling for nonlinear packaging stresses, 

ASME Journal of Electronic Packaging, 125(4), 490-497, (2003) 

W.D. van Driel, G.Q. Zhang, J.H.J. Janssen, Prediction and verification of process induced warpage of 

electronic packages, Journal of Microelectronics Reliability, 43(5), 765-774, (2003) 

R.A.B. Engelen, M.G.D. Geers, F.P.T. Baaijens, Nonlocal implicit gradient-enhanced elasto-plasticity for the 

modelling of softening behaviour, Int. J. Plasticity, 19(4), 403-433, (2003) 

M.G.D. Geers, R.L.J.M. Ubachs, R.A.B. Engelen, Strongly nonlocal gradient-enhanced finite strain 

elastoplasticity, Int. J. Numer. Meth. Engng, 56(14), 2039-2068, (2003) 

E.M. Viatkina, W.A.M. Brekelmans, M.G.D. Geers, Strain path dependency in metal plasticity, Journal de 

Physique IV, 105, 355-362, (2003) 

2004 

M.E. Erinc, P.J.G. Schreurs, G.Q. Zhang, M.G.D. Geers, Characterization and fatigue damage simulation in 

SAC solder joints, Microelectronics Reliability, 44(9), 1287-1292, (2004). 

L.P. Evers, W.A.M. Brekelmans, M.G.D. Geers, Non-local crystal plasticity model with intrinsic SSD and 

GND effects, J. Mech. Phys. Solids, 52(10), 2379-2401, (2004). 

L.P. Evers, W.A.M. Brekelmans, M.G.D. Geers, Scale dependent crystal plasticity framework with 

dislocation density and grain boundary effects, Int. J. Solids Structures, 41(18-19), 5209-5230, (2004). 

M.G.D. Geers, Preface to Special Issue on Multiscale Computational Homogenization: From 

Microstructure to Properties, Int. Jnl. Multiscale Comp. Eng., 2(4), 507-510, (2004). 

V.G. Kouznetsova, M.G.D. Geers, W.A.M. Brekelmans, Multi-scale second-order computational 

homogenization of multi-phase materials: a nested finite element solution strategy, Comput. Methods. 

Appl. Mech. Engrg., 193(48-51), 5525-5550, (2004). 

V.G. Kouznetsova, M.G.D. Geers, W.A.M. Brekelmans, Size of a representative volume element in a 

second-order computational homogenization framework, Int. Jnl. Multiscale Comp. Eng., 2(4), 575-598, 

(2004). 

A. Matin, W.P. Vellinga, M.G.D. Geers, Aspects of coarsening in eutectic Sn-Pb, Acta Mat., 52(12), 3475- 

3482, (2004). 

R.H.J. Peerlings, N.A. Fleck, Computational evaluation of strain gradient elasticity constants, Int. Jnl. 

Multiscale Comp. Eng., 2(4), 599-620, (2004). 

R.L.J.M. Ubachs, P.J.G. Schreurs, M.G.D. Geers, A nonlocal diffuse interface model for microstructure 

evolution of tin-lead solder, J. Mech. Phys. Solids, 52(8), 1763-1792, (2004). 

R.L.J.M. Ubachs, P.J.G. Schreurs, M.G.D. Geers, Microstructure Evolution of Tin-Lead Solder, IEEE Trans. 

on Components and Pack. Tech., 27(4), 635-642, (2004). 

63



A.J.J. Abdul-Baqi, P.J.G. Schreurs, M.G.D. Geers, Fatigue damage modeling in solder interconnects using a 

cohesive zone approach, Int. J. Solids Structures, 42, 927-942, (2005) 

A. Aydemir, J.H.P. de Vree, W.A.M. Brekelmans, M.G.D. Geers, W.H. Sillekens, R.J. Werkhoven, An 

adaptive simulation approach designed for tube hydroforming processes , J. Mat. Proc. Techn., 159, 303-310, 

(2005) 

S.H.A. Boers, P.J.G. Schreurs, M.G.D. Geers, Operator-split damage-plasticity applied to groove forming in 

food can lids, Int. J. Solids Structures, 42(14), 4154-4178, (2005) 

M.E. Erinc, P.J.G. Schreurs, G.Q. Zhang, M.G.D. Geers, Microstructural damage analysis of snagcu solder 

joints and an assessment on indentation procedures, J. Mat. Sci., 16, 693-700, (2005) 

M.G.D. Geers, V.G. Kouznetsova, W.A.M. Brekelmans, Multi-scale mechanics in micro-electronics: a 

paradigm in miniaturization, Journal of Electronic Packaging, 127(3), 255-261, (2005) 

T.J. Massart, R.H.J. Peerlings, M.G.D. Geers, A dissipation-based control method for the multi-scale 

modelling of quasi-brittle materials, C. R. Mecanique, 333, 521–527, (2005) 

A. Matin, E.W.C. Coenen, W.P. Vellinga, M.G.D. Geers, Correlation between thermal fatigue and thermal 

anisotropy in a Pb-free solder alloy, Scripta Materialia, 53, 927-932, (2005) 

R.P. Schaake, W.P. Vellinga, J.M.J. den Toonder, H.E.H. Meijer, One minute wear rate measurement, 

Macromolecular Rapid Communications, 26(--), 188, (2005) 

R.L.J.M. Ubachs, P.J.G. Schreurs, M.G.D. Geers, Phase field dependent viscoplastic behaviour of solder 

alloys, Int. J. Solids Structures, 42(9-10), 2533-2558, (2005) 

E.M. Viatkina, W.A.M. Brekelmans, M.G.D. Geers, A crystal plasticity based estimate for forming limit 

diagrams from textural inhomogeneitiess, J. Mat. Proc. Techn., 168(2), 211-218, (2005) 

64

Nano-engineering / cNM Plasma-Based Synthesis of Thin Films and Nanostructures 

Plasma-Based Synthesis of Thin Films and Nanostructures 

M.C.M. van de Sanden/D.C. Schram 

Plasmas, a highly nonequilibrium and excited medium, enable the design and processing of thin 

films and nanostructures with greater freedom than normal synthesis techniques because the 

reactivity is transferred from the substrate to the gas phase. Therefore the combination of plasma 

processing techniques with well established nanoscale bottom-up growth techniques such as 

atomic layer deposition and epitaxy overcomes the usual restrictions in equilibrium (surface) 

chemistry. This opens up new approaches and opportunities to obtain thin films and 

nanostructures not possible with strictly chemical or physical methods. Additional advantages of 

the use of plasma-based synthesis techniques is the enhanced throughput and the presence of 

charge and electrical fields which enables the controlled growth of directed nanostructures such 

as nanowires and nanocrystals. 


1. Controlled synthesis of thin films and nanostructures by plasmas. Development of plasmabased 

synthesis techniques. Two approaches will be investigated 1) the controlled growth 

of nanostructured films and nanostructures by plasmas and 2) plasma-aided atomic layer 

deposition for processing at the nanoscale. 

2. Surface atomistic reactions during plasma-based synthesis. Study of the key surface reactions 

during the synthesis of thin films and nanostructures that determine the final material 

and device properties and whose understanding allows future process and material 

properties manipulation. Development of novel and in situ surface and film optical 

diagnostics with submonolayer sensitivity and with femtosecond resolution. 

Keywords 

Plasma-based synthesis, plasma-aided atomic layer deposition, in situ surface and film diagnostics, 

surface atomistic reactions 




PhD 5.0 4.0 




R. Groenen, J.L. Linden, H.R.M. van Lierop, D.C. Schram, A.D. Kuypers, M.C.M. van de Sanden, 

An expanding thermal plasma for deposition of surface textured ZnO:Al with focus on thin film solar cell 

applications, Appl. Surface Sci. 173 (2001) 40-43 

W.M.M. Kessels, D.C. Marra, M.C.M. van de Sanden, E.S. Aydil, In situ probing of surface hydrides 

on hydrogenated amorphous silicon using attenuated total reflection infrared spectroscopy, J. Vac. Sci 

Technol. A 20 (2002) 781-789 

65


A.H.M. Smets, W.M.M. Kessels, M.C.M. van de Sanden, Vacancies and voids in hydrogenated 

amorphous silicon, Appl. Phys. Lett. 82 (2003) 1547-1549 

J. Hong, W.M.M. Kessels, F.J.H. van Assche, H.C. Rieffe, W.J. Soppe, A.W. Weeber, 

and M.C.M. van de Sanden, Bulk passivation of multicrystalline silicon solar cells induced by high-rate 

deposited(>1 nm/s) silicon nitride films, Progress in Photovoltaics: Research and Applications 11 

(2003) 125-130 

I.M.P. Aarts, B. Hoex, A.H.M. Smets, R. Engeln, W.M.M. Kessels, M.C.M. van de Sanden, Direct 

and highly sensitive measurement of defect-related absorption in amorphous silicon thin films by cavity 

ringdown spectroscopy, Appl. Phys. Lett. 84 (2004) 3079-3081 


Thin films have been produced by plasma-assisted atomic layer 

deposition, which is the ultimate technique when processing at 

the nanoscale. With this technique, it is possible to grow ultrathin 

and conformal films and nanolaminates and it can be used to give 

functionality to high-area surfaces, etc. In a novel approach, 

plasmas are applied for widening and enabling new process 

conditions and materials (especially single-element metals) as well 

as to reduce processing temperature. So far, TiN films have been 

deposited from TiCl4 vapor and N2-H2 plasmas for applications 

such as diffusion barriers, metal gates, and high-density 

capacitors. 

In our effort to 

investigate key material 

Absolute Erbium Absorption (10 -5 ) 

12 

10 

8 

6 

4 

2 

mirror 

laser pulse 

0 

1450 1500 1550 1600 

Wavelength (nm) 

properties and to 

monitor film growth and 

surface reactions in real 

time, we have recently 

developed a novel and innovative optical technique to 

measure absolute densities of low concentration defects 

and dopants in thin films. With this technique, it has 

been possible (for the first time) to measure the 

absolute absorption cross-section of erbium in silica 

doped with silicon nanocrystals. The nanocrystals in 

these films, which can be synthesized by a plasma- 

based process, affect the optical amplification of erbium for nanophotonic waveguideapplications, 

etc. At the moment the extension to evanescent wave cavity ring down spectroscopy 

is explored using a folded cavity design. This will enable in situ study of thin film growth on the 

atomic scale and with ultrahigh sensitivity. Optical losses as low as 2.5 10 -8 have been detected. 


sample 

mirror 

Dr.ir. W.M.M. Kessels 

Mainly involved in the plasma-based synthesis of (new) materials and nanostructured thin films 

as well as in the investigation of the underlying fundamental mechanisms of the growth process 

and the material properties (plasma and surface reactions, surface science aspects, advanced 

spectroscopy). 

66


Prof.dr.ir. M.C.M. van de Sanden 

Explores the potential of plasma processing with respect to the synthesis of new materials, 

nanostructures, and devices. This effort is carried out in collaboration with several university, 

institutional and industrial partners. 

Selected publications 1999-2003 

1999 

A.P. Dementjev, A. de Graaf, D.I. Dolgiy, E.D. Olshanski, Y.M. Shulga, A.A. Serov, CNx film characterization 

by surface sensitive methods: XPS and XAES, Diamond and Related Materials 8 (1999) 601-604 

R. Engeln, K.G.Y. Letourneur, M.G.H. Boogaarts, M.C.M. van de Sanden, D.C. Schram, Detection of CH in 

an expanding argon/acetylene plasma using cavity ringdown absorption spectroscopy, Chem. Phys. Lett. 310 

(1999) 405-410 

W.M.M. Kessels, C.M. Leewis, M.C.M. van de Sanden, D.C. Schram, Formation of cationic silicon clusters in a 

remote silane plasma and their contribution to hydrogenated amorphous silicon film growth, J. Appl. Phys. 86 

(1999) 4029-4039 

W.M.M. Kessels, C.M. Leewis, A. Leroux, M.C.M. van de Sanden, D.C. Schram, Formation of large positive 

silicon-cluster ions in a remote silane plasma, J. Vac. Sci. Technol. A 17 (1999) 1531-1535 

M.C.M. van de Sanden, W.M.M. Kessels, R.J. Severens, D.C. Schram, Plasma and surface chemistry effects 

during high rate deposition of hydrogenated amorphous silicon, Plasma Phys. Control. Fusion 41 (1999) A365- 

A378 

A.H.M. Smets, M.C.M. van de Sanden, D.C. Schram, In situ ellipsometric studies of the a-Si:H growth using an 

expanding thermal plasma, Thin Solid Films 343-344 (1999) 281-284 

2000 

G.J. Adriaenssens, H.-Z. Song, V.I. Arkhipov, E.V. Emelianova, W.M.M. Kessels, A.H.M. Smets, B.A. 

Korevaar, M.C.M. van de Sanden, Analysis of time-of-flight photocurrents in a-Si:H deposited by expanding 

thermal plasma, J. Optoelectronics and Advanced Materials 2 (2000) 31-42 

M.G.H. Boogaarts, P.J. Böcker, W.M.M. Kessels, D.C. Schram, M.C.M. van de Sanden, Cavity ringdown 

detection of SiH3 on the broadband A 2 A ' 1 transition in a remote Ar-H2-SiH4 plasma, Chem. Phys. Lett. 326 

(2000) 400-406 

A.P. Dementjev, A. de Graaf, M.C.M. van de Sanden, K.I. Maslakov, A.V. Naumkin, A.A. Serov, X-Ray 

photoelectron spectroscopy reference data for identification of the C3N4 phase in carbon-nitrogen films, Diamond 

and Related Materials 9 (2000) 1904-1907 

W.M.M. Kessels, M.C.M. van de Sanden, R.J. Severens, D.C. Schram, Surface reaction probability during fast 

deposition of hydrogenated amorphous silicon with a remote silane plasma, J. Appl. Phys. 87 (2000) 3313-3320 

W.M.M. Kessels, M.C.M. van de Sanden, D.C. Schram, Film growth precursors in a remote SiH4 plasma used 

for high-rate deposition of hydrogenated amorphous silicon, J. Vac. Sci. Technology A 18 (2000) 2153-2163 

B.A. Korevaar, G.J. Adriaenssens, A.H.M. Smets, W.M.M. Kessels, H.-Z. Song, M.C.M. van de Sanden, 

D.C. Schram, High hole drift mobility in a-Si:H deposited at high growth rates for solar cell application, J. Non- 

Crystalline Solids 266-269 (2000) 380-384 

A.H.M. Smets, D.C. Schram, M.C.M. van de Sanden, In situ single wavelength ellipsometry studies of high rate 

hydrogenated amorphous silicon growth using a remote expanding thermal plasma, J. Appl. Phys. 88 (2000) 

6388-6394 

R.A.C.M. van Swaaij, M. Zeman, B.A. Korevaar, C. Smit, J.W. Metselaar, M.C.M. van de Sanden, Challenges 

in amorphous silicon solar cell technology, Acta Physica Slovaca 50 (2000) 559-570 

67


2001 

R. Groenen, J.L. Linden, H.R.M. van Lierop, D.C. Schram, A.D. Kuypers, M.C.M. van de Sanden, An 

expanding thermal plasma for deposition of surface textured ZnO:Al with focus on thin film solar cell applications, 

Appl. Surface Sci. 173 (2001) 40-43 

R. Groenen, J. Löffler, P.M. Sommeling, J.L. Linden, E.A.G. Hamers, R.E.I. Schropp, M.C.M. van de 

Sanden, Surface textured ZnO films for thin film solar cell applications by expanding thermal plasma CVD, Thin 

Solid Films 392 (2001) 226-230 

E.A.G. Hamers, A.H.M. Smets, C. Smit, J.P.M. Hoefnagels, W.M.M. Kessels, M.C.M. van de Sanden, 

Material properties and growth process of microcrystalline silicon with growth rates in excess of 1 nm/s, Mater. Res. 

Soc. Symp. Proc. 664 (2001) A.4.2.1 

W.M.M. Kessels, R.J. Severens, A.H.M. Smets, B.A. Korevaar, G.J. Adriaenssens, D.C. Schram, M.C.M. van 

de Sanden, Hydrogenated amorphous silicon deposited at very high growth rates by an expanding Ar-H2-SiH4 

plasma, J. Appl. Phys. 89 (2001) 2404-2413 

W.M.M. Kessels, A.H.M. Smets, D.C. Marra, E.S. Aydil, D.C. Schram, M.C.M. van de Sanden, On the 

growth mechanism of a-Si:H, Thin Solid Films 383 (2001) 154-160 

W.M.M. Kessels, J.P.M. Hoefnagels, M.G.H. Boogaarts, D.C. Schram, M.C.M. van de Sanden, Cavity ring 

down study of the densities and kinetics of Si and SiH in a remote Ar-H2-SiH4 plasma, J. Appl. Phys. 89 (2001) 

2065-2073 

J. Löffler, R. Groenen, J.L. Linden, M.C.M. van de Sanden, R.E.I. Schropp, Amorphous silicon solar cells on 

natively textured ZnO grown by PECVD, Thin Solid Films 392 (2001) 315-319 

J. Löffler, R. Groenen, P.M. Sommeling, J.L. Linden, M.C.M. van de Sanden, R.E.I. Schropp, Structural, 

optical and electrical properties of natively textured ZnO grown by PECVD for Thin-Film Solar Cell Applications, 

Solid State Phenomena 80-81 (2001) 145-150 

2002 

S. Agarwal, A. Takano, M.C.M. van de Sanden, D. Maroudas, E.S. Aydil, Abstraction of atomic hydrogen by 

atomic deuterium from an amorphous hydrogenated silicon surface, J. Chem. Phys. 117 (2002) 10805-10816 

G.R. Alcott, J.L. Linden, M.C.M. van de Sanden, Gas phase deposition of hybrid coatings, Mat. Res. Soc. Symp. 

Proc. 726 (2002) Q9.9.1 

M. Brinza, G.J. Adriaenssens, K. Iakoublovskii, A. Stesmans, W.M.M. Kessels, A.H.M. Smets, M.C.M. van 

de Sanden, Time-of-flight photocurrents in expanding-thermal-plasma-deposited a-Si:H, J. Non-Cryst. Solids 

299-302 (2002) 420-424 

M. Creatore, M.F.A.M. van Hest, J. Benedikt, M.C.M. van de Sanden, Expanding thermal plasma deposition of 

silicon dioxide-like films for microelectronic devices, Mat. Res. Soc. Symp. Proc. 715 (2002) A19.3.1 

R. Groenen, E.R. Kieft, J.L. Linden, R.E.I. Schropp, M.C.M van de Sanden, Textured zinc oxide by expanding 

thermal plasma CVD: the effect of aluminium doping, Mat. Res. Soc. Symp. Proc. 730 (2002) V3.9.1 

J.P.M. Hoefnagels, A.A.E. Stevens, M.G.H. Boogaarts, W.M.M. Kessels, M.C.M. van de Sanden, Timeresolved 

cavity ring-down spectroscopic study of the gas phase and surface loss rates of Si and SiH3 plasma radicals, 

Chem. Phys. Lett. 360 (2002) 189-193 

W.M.M. Kessels, D.C. Marra, M.C.M. van de Sanden, E.S. Aydil, In situ probing of surface hydrides on 

hydrogenated amorphous silicon using attenuated total reflection infrared spectroscopy, J. Vac. Sci Technol. A 20 

(2002) 781-789 

W.M.M. Kessels, J. Hong, F.J.H. van Assche, J.D. Moschner, T. Lauinger, W.J. Soppe, A.W. Weeber, D.C. 

Schram, M.C.M. van de Sanden, High-rate deposition of a-SiNx:H for photovoltaic applications by the expanding 

thermal plasma, J. Vac. Sci. Technol. A 20 (2002) 1704-1715 

68


W.M.M. Kessels, P.R. McCurdy, K.W. Williams, G.R. Barker, V.A. Ventura, and E.R. 

Fisher, Surface reactivity and plasma energetics of SiH radicals during deposition of 

silicon-based materials, J. Phys. Chem. B 106 (2002) 2680-2689 

C. Smit, E.A.G. Hamers, B.A. Korevaar, R.A.C.M.M. van Swaaij, M.C.M. van de Sanden, Fast deposition of 

microcrystalline silicon with an expanding thermal plasma, J. Non-Cryst. Solids 299-302 (2002) 98-102 

2003 

S. Agarwal, B. Hoex, M.C.M. van de Sanden, D. Maroudas, E.S. Aydil, Absolute densities of N and excited N2 

in a N2 plasma, Appl. Phys. Lett. 83 (2003) 4918-4920 

J. Benedikt, R.V. Woen, S.L.M. van Mensfoort, V. Perina, J. Hong, M.C.M. van de Sanden, Plasma chemistry 

during the deposition of a-C:H films and its influence on film properties, Diamond Rel. Mater. 12 (2003) 90-97 

G.J.H. Brussaard, K.G.Y. Letourneur, M. Schaepkens, M.C.M. van de Sanden, D.C. Schram, 

Stripping of photoresist using a remote thermal Ar/O2 and Ar/N2/O2 plasma, J. Vac. Sci. Technol. B 21 (2003) 

61-66 

M. Creatore, Y.Barrell, W.M.M. Kessels, M.C.M. van de Sanden, Expanding thermal plasma for low-k 

dielectrics deposition, Mat. Res. Soc. Symp. Proc. 766 (2003) E6.9.1-E.6.9.6 

G. Dinescu, M. Creatore, M.C.M. van de Sanden, Remote nitridation of silicon surface by Ar/N2-fed expanding 

thermal plasma, Surf. Coat. Technol.174-175 (2003) 370-374 

M.F.A.M. van Hest, A. Klaver, D.C. Schram, M.C.M. van de Sanden, Argon-oxygen plasma treatment of 

deposited organosilicon thin films, Thin Solid Films (2003) 

J. Hong, W.M.M. Kessels, F.J.H. van Assche, H.C. Rieffe, W.J. Soppe, A.W. Weeber, 

and M.C.M. van de Sanden, Bulk passivation of multicrystalline silicon solar cells induced by high-rate 

deposited(>1 nm/s) silicon nitride films, Progress in Photovoltaics: Research and Applications 11 (2003) 125- 

130 

J. Hong, W.M.M. Kessels, W. J. Soppe, A.W. Weeber, W.M. Arnoldbik, and M.C.M. van de Sanden, 

Influence of the high-temperature “firing” step on high-rate plasma deposited silicon nitride films used as bulk 

passivating antireflection coatings on silicon solar cells, J. Vac. Sci. Technol. B 21 (2003) 2123-2132 

W.M.M. Kessels, J.P.M. Hoefnagels, P.J. van den Oever, Y. Barrell, M.C.M. van de Sanden, Temperature 

dependence of the surface reactivity of SiH3 radicals and the surface silicon hybride composition during amorphous 

silicon growth, Surf. Sci. Lett. 547 (2003) L865-L870 

D.C. Marra, W.M.M. Kessels, M.C.M. van de Sanden, K. Kashefizadeh, E.S. Aydil, Surface hydride 

composition of plasma deposited hydrogenated amorphous silicon: situ infrared study of ion flux and temperature 

dependence, Surf. Sci. 530 (2003) 1-16 

A.M.H.N. Petit, M. Zeman, R.A.C.M.M. van Swaaij, M.C.M. van de Sanden, Simulation of buffer layers in a- 

Si:H thin film solar cells deposited with an expanding thermal plasma, Mat. Res. Soc. Symp. Proc. 762 (2003) 

369-374 

A.H.M. Smets, W.M.M. Kessels, M.C.M. van de Sanden, Temperature dependence of the surface roughness 

evolution during hydrogenated amorphous silicon film growth, Appl. Phys. Lett. 82 (2003) 865-867 

A.H.M. Smets, W.M.M. Kessels, M.C.M. van de Sanden, Vacancies and voids in hydrogenated amorphous 

silicon, Appl. Phys. Lett. 82 (2003) 1547-1549 

C. Smit, R.A.C.M.M. van Swaaij, H. Donker, A.M.H.N. Petit, W.M.M. Kessels, M.C.M. van de Sanden, 

Determining the material structure of microcrystalline silicon from Raman spectra, J. Appl. Phys. 94 (2003) 3582- 

3588 


69


I.M.P. Aarts, A.C.R. Pipino, J.P.M. Hoefnagels, W.M.M. Kessels, and M.C.M. van de Sanden, Quasi-Ice 

Monolayer on Atomically Smooth Amorphous SiO2 at Room Temperature Observed with a High-Finesse 

Optical Resonator, Phys. Rev. Lett. 95 (2005) 166104 

S.B.S. Heil, E. Langereis, A. Kemmeren, F. Roozeboom, M.C.M. van de Sanden, and W.M.M. Kessels, 

Plasma-assisted atomic layer deposition of TiN monitored by in situ spectroscopic ellipsometry, J. Vac. Sci. 

Technol. A 23 (2005) L5-L8 

H. Mertens, A. Polman, I.M.P. Aarts, W.M.M. Kessels, and M.C.M. van de Sanden, Absence of the 

enhanced intra-4f transition cross section at 1.5 µm of Er3+ in Si-rich SiO2, Appl. Phys. Lett. 86 (2005) 

241109 

A.H.M. Smets, W.M.M. Kessels, and M.C.M. van de Sanden, Surface-diffusion-controlled incorporation of 

nanosized voids during hydrogenated amorphous silicon film growth, Appl. Phys. Lett. 86 (2005) 041909 

70

Nano-engineering / cNM Micro- and Nano-sale Engineering 

Micro- and Nano- scale Engineering A.H. Dietzel 

In the summer of 2004 Andreas Dietzel started as holder of the newly established full chair for 

Micro- and Nano- scale Engineering. The focus of the new research group will differ to a farreaching 

extent from that of the former Precision Engineering group. In view of this, the new 

group will be strengthened by new staff members. 

Research Themes 

The new group shall establish research activities in the following areas: 

Micro- and nano-scale structuring and fabrication. For example, new fabrication processes are 

needed for future disposable devices. Techniques and materials that allow the replication of 

micro- and nano-structures in polymeric materials with specific properties shall be investigated. 

Micro- sensor and actuator systems and micro-fluidic systems. Special emphasis shall be placed 

on techniques that will be important for new biosensor devices. Furthermore, the behavior of 

micro- and nano-structured solids and of fluids in micro- or nano-scaled environments shall be 

studied with suitable experimental set-ups. Models describing the phenomena shall be developed 

and shall help to design micro-mechanical or micro-fluidic devices for specific applications, 

Techniques for hybrid or even monolithic integration. Integration of sensors and actuators (magnetic, 

optical, electrical) in micro-fluidic or micro-mechanical environments shall be investigated. 

The research in this group shall permit looking for integrated systems. We will aim at proving 

new concepts by building demonstrator devices. 

Keywords 

Micro- and nano- fabrication, micro- sensors and actuators, micro- fluidics, integrated systems 

Research Outlook 

The limits of injection molding shall be investigated and suitable models for the filling of highaspect-ratio 

micro-cavities with the mold material shall be developed. Micro- or even nanostructured 

master surfaces shall be formed using photon- or electron-lithography techniques and 

deep-reactive ion etching (DRIE) techniques. For micro-fluidic bio-chip applications closed 

channels will be required. Techniques for the closure of micro-channels or micro-cavities shall be 

found. 

Micro-cavities for specific fluid treatments shall be designed and tested. Techniques have to be 

found allowing mixing small fluid volumes with bio-reagents. Moreover, bio-molecules which can 

be found in the fluids in low concentrations shall be effectively brought into contact with a bioactivated 

sensor surface. 

In the metrology sensor project named “Nanoprobe” emphasis shall be placed on developing 

assembly techniques for a miniaturized mechanical probe head, e.g. using micro-grippers. 

Surface effects like sticktion and friction play an increasing role for the assembly of objects with 

reduced dimensions and means to control or compensate these effects have to be found. 

Furthermore, we will investigate possibilities of monolithic integration of previously hybrid 

system components. New designs for the nanoprobe components which are compatible with 

planar MEMS fabrication processes shall be evaluated. 

71

Nano-engineering / cNM Micro- and Nano-sale Engineering 

Finally, we will integrate the mechanical design competencies in our research strategy. The 

design principles that were very successfully applied in many precision engineering systems shall 

be utilized in the context of new micro- and nano-engineering projects. We currently see 

opportunities to develop machines and processes that find applications in the micro-fabrication, 

e.g. for lithography techniques that accommodate specific requirements of the fabrication of 

MEMS devices. 

72

Annual report 2005 - Eindhoven University of Technology

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