Proceedings of the European Summer School of Photovoltaics 4 – 7 ...

Research achievements of the DSOD Lodz in the field
of photovoltaics
Katarzyna Znajdek, Maciej Sibiński
Technical University of Lodz, Department of Semiconductor and Optoelectronic Devices
The Department of Semiconductor and Optoelectronics Devices
was established in 2008 as a part of the Faculty of Electrical,
Electronic, Computer and Control Engineering at the Technical
University of Lodz in Poland. The team of the DSOD Lodz consists
of two professors, two associate professors, nine doctors,
five PhD students and seven technical and administration employees.
The Department’s research activities cover optoelectronic,
micro- and nanoelectronic technologies, modeling and analysis of
electrical and thermal phenomena in semiconductor devices, as
well as designing and manufacturing of semiconductor devices,
including solar cells. The main fields of the research interest are
power semiconductor devices, high temperature electronics with
emphasis on SiC technology, integrated intelligent systems, photonic
systems and photovoltaic cells [1].
Resources and technological base
Both teaching and research activities are conducted in the
Department’s laboratories which enable investigation and experiments
covering designing, manufacturing and testing of photovoltaic
devices. Laboratories’ equipment base of the DSOD at TUL
covers among others:
• Technological Centre of Microtechnology comprising Clean-
Room laboratory, equipped with the facilities for fabrication
and characterization of semiconductor or metal thin films, as
well as for mapping of designed semiconductor structures.
• Optoelectronics under the patronage of Corning Cable Systems
Poland
• Hybrid Systems Laboratory, equipped, inter alia, with the
pneumatic screen printer, the ball mill and the station for screen
printing pastes preparation.
• Photovoltaic Laboratory, fully equipped with an integrated
measurement system that simulates standard test conditions
STC, in accordance to the requirements of IEC 60904-1 and
IEC 60904-3. The system includes C class solar simulator (in
accordance to IEC 60904-9) with a silicon photodetector that
controls the stability of the light source.
• Specialized program SCAPS (Solar Cell Capacitance Simulator)
for comprehensive simulations of solar cells dedicated to
develop physical models and simulate new photovoltaic device
structures.
DSOD’s Laboratory of Photovoltaics, apart from technological
and measuring equipment, possesses its own micro power solar
plant of 2 kW p
, consisted of four various types of photovoltaic arrays:
– multicrystalline silicon: M-Si (6 modules of 115 W p
each),
– ribbon silicon: R-Si (6 modules of 110 W p
each),
– amorphous silicon: α-Si (6 modules of 64 W p
each),
– cooper indium diselenide: CIS (6 modules of 40 W p
each).
The installation is connected to the internal grid through Sunny
Boy inverters, independently for each array type, which are
then attached together by Sunny Boy Control Plus for data collection.
All parameters of the PV plant are monitored and archived
in the computer server located in the Laboratory. Moreover,
they can be observed in the real time conditions, by anyone (with
no password or special access permission needed), via the PV
Laboratory’s web site: http://www.fotowoltaika.dsod.pl [2]. Electricity
produced by solar panels is used for the University internal
power demands.
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Research projects currently being realized
Among seven currently running scientific projects in the Department
of Semiconductor and Optoelectronics Devices, two of them
are being realized in the field of photovoltaics. One of them is
Polish research project granted by the National Science Centre
within the program Opus (general grant). The other one is a project
supporting international cooperation granted by the Ministry of
Science and Higher Education under the Polonium program.
Opus: Transparent emitter electrode for PV
applications based on carbon nanotubes
This project is being realized by DSOD Lodz as a leader, in cooperation
with two other Polish research centers, which are: Institute
of Electronic Materials Technology of the Warsaw University
of Technology and Institute of Fluid-Flow Machinery of the Polish
Academy of Sciences. It has been granted by the National Science
Centre for two years, from January 2012 to December 2013.
The aim of the project is to manufacture transparent conductive
layers, based on carbon nanotubes (CNT), and apply them
as front electrodes of various types solar cells. Obtaining thin,
flexible transparent layers is to be achieved by using low-cost manufacturing
techniques, such as screen printing, and by utilizing
crude, easily available nanotube material with organic media.
Created layers would replace currently used conductive oxides,
such as ITO or ZnO: Al. Their application as transparent contacts
in photovoltaic structures would eliminate certain disadvantages
of previously used electrodes, such as fracturing in flexible photovoltaic
structures. Additionally, exploration possibilities of new
devices, manufacturing in roll-to-roll process, with no use of expensive
vacuum technology, is planned [3].
The following research work are scheduled in the project:
– Preparation of carbon nanotube based suspensions of various
composition and percentage, testing their properties and developing
techniques, allowing to deposit controlled layer on test
substrates. Simultaneously, a number of selected conductive
oxide samples, including indium tin oxide ITO, ZnO 2
and ZnO:
Al, is expected to be manufactured, in order to compare optoelectronic
and mechanical properties of new and traditional
Fig. 1. Composition containing 0.25% carbon nanotubes printed on
glass substrate
Elektronika 6/2012