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Solar radiation is both a renewable and sustainable source of energy,
which can address the challenging energy demands of our growing society.
Photovoltaic (PV) devices are used to convert solar radiation to electricity.
Photons are absorb by the PV material (semiconductor) in the device and
their energy generates charge carriers (holes and electrons), thereby
producing electricity. Novel PV materials are being developed to improve
their efficiency and decrease their manufacturing cost.
Quantum dots (QDs) that are capable Multiple Exciton Generation (MEGs)
when excited by one high-energy photon in the solar spectrum can increase
the energy conversion efficiencies. Lead sulfide (PbS) absorbs in the
near-infrared, thus the wide spectrum of solar radiation will generate
MEGs in higher efficiency. A scaffold is required to rapidly transport
the charge carriers to the electrodes. The delocalization of pi electrons
in single-wall carbon nanotubes (SWCNTs) along the tubes axis makes it
a prime candidate for charge transfer and transport. SWCNTs have a reported
carrier mobility which is nearly 100 times higher than that in Si and
4 times that of organic semiconductors.
The aim of this project is to optimize the transport properties SWCNT-QDs
for the development of successful PV applications. The local interaction
between the QD and SWCNT is important for fast charge transfer, which
requires large close area contact. I plan to investigate the transport
properties of QDs/SWCNTs using scanning tunneling microscopy/spectroscopy
(STM/STS) and correlate local I-V characteristics with structural properties
with the aim of optimizing device performance.
A. Book Chapter
Moonoosawmy, K.R., Macleod, J. M, Rosei, F. (2010) STM
characterization of supramolecular materials with potential for organic
electronics and nanotechnology. In Functional supramolecular architectures
for organic electronics and nanotechnology Edited by Cacialli, F and Samorì,
F., Wiley-VCH.
Moonoosawmy, K.R., Kruse, P. (2010) Keeping track of
the electronic properties of single-walled carbon nanotubes during chemical
processing. In Electronic and Catalytic Properties of Advanced Materials
Edited by A. Stashans, S. González and H. Pinto., Research Signpost.
B. Refereed Journal Publications
Moonoosawmy, K.R., Kruse, P.(2010) Cause and Consequence
of Carbon Nanotube Doping in Water and Aqueous Media, J. Am. Chem. Soc.
2010, 132, 1572–1577
Moonoosawmy, K.R., Kruse, P. (2009) Ambiguity in the
Characterization of Chemically modified Single Wall Carbon Nanotubes:
A Raman and UV-vis-NIR study, J. Phys. Chem. C. 113 (13), 5133–5140
Moonoosawmy, K.R., Kruse, P. (2008) To dope or not to
dope: The effect of sonicating Single Wall Carbon Nanotubes in common
lab solvents on their electronic structure, J. Am. Chem. Soc. 130, 13417–13424
Article highlighted in both:
1. World
Chemistry from the Royal Society of Chemistry, England
2. Nanowerk,
Top Nanotechnology News Headlines
Cahill, L.S., Yao, Z., Adronov, A.,Penner, J., Moonoosawmy, K.R.,
Kruse, P., and Goward. G.R.; J. Phys. Chem. B; Polymer-Functionalized
Carbon Nanotubes Investigated by Solid-state Nuclear Magnetic Resonance
and Scanning Tunnelling Microscopy, 2004, 108, 11412
Worsley A. K., Moonoosawmy K. R., Kruse, P.(2004) Nanoletters;
Long-Range Periodicity in Carbon Nanotube Sidewall Functionalization,
4(8), 1541
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