2011 Annual Report - Center for Integrated Nanotechnologies - Los ...

Nanophotonics & Optical Nanomaterials Thrust
in less-explored CNT-metal complexes and use spectroelectrochemistry
to study single CNTs. In the case of other 1D and even
2D structures, we will study nanowire heterostructures using ultrafast
optical microscopy to shed light on their use in solar cells
and nanoscale transistors, as well as using ultrafast optical and
terahertz spectroscopy to unravel the interplay between different
order parameters in magnetic/superconducting and ferroelectric/
magnetic heterostructures. We can apply mid-infrared pump,
terahertz-probe spectroscopy to the interaction between phonons
and electrons in high-Tc superconductors, and we plan to
develop a terahertz time-domain spectroscopy system in a strong
magnetic field and apply it to studying the quantum Hall effect in
graphene and two-dimensional electron gases. A new time-resolved
PL system will be installed at the CINT Core, which will be
used initially to study PL dynamics of semiconductor nanowires
as a function of temperature. We will expand the work of coupled
semiconductor heterostructures with metamaterials to include
InGaAs and GaSb materials, parabolic quantum wells, etc. and
combine nanowires in a 2D photonic crystal arrangement to
study laser emission with the goal of reducing lasing threshold
to a record low. In the area of CNTs, we will extend investigations
into the origins of non-Condon behavior in nanotube Raman
response to determine its extent in armchair structures and for
high-energy excitations. We will use strain to realize tunability of
the non-Condon response and Raman interference behavior.
We will enhance our single-tube near-IR photoluminescence
capability by including a time-correlated single-photon counting
capability, correlation spectroscopies, and addition of a tunable
ps continuum excitation source. We will also pursue aerogel-CNT
composites as optical cavities and for fundamental photophysical
studies including probing of nanotube energy transfer behaviors
and as new matrices for studying recently introduced empty
nanotubes. Lastly, in addition to further fundamental explorations
through advanced spectroscopic methods, our work in 0D optical
nanomaterials will continue to include development of synthetic
methods for novel functional NQDs, as well as new approaches
for separating sub-ensembles of nanoparticles based on function
that result, for example, from less-than fully homogeneous
reaction conditions, including a new electrophoretic separation
method. We also intend to develop new synthetic methods for
fabrication of inverted nanoshell plasmonic-fluorophore coupled
systems, especially infrared-emitting, toward intrinsic control
of emitter radiative/nonradiative properties. Our existing nonblinking
NQDs will be used in 3D particle tracking studies to facilitate
fundamental understanding in cell membrane science and
drug-tumor interactions. We will also purchase and perform initial
experiments with a Nanoink, Inc. DPN 5000 nanolithography system
to be installed at the CINT Gateway, including realization of
nanoscale control over optical nanomaterial/metal nano-antenna
integration.
Members of the NPON Thrust at the Core Facility.
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