Dear group,
Tomorrow Thursday, at 2:30pm in the Division Room (M102), we will have a
talk by Tamar Mentzel, a postdoctoral candidate from the Kastner group
(MIT). Tamar's background is mostly in experimental work. She is now
interested in doing research in simulation/modeling. Please find below the
title and abstract of her talk.
Tamar Mentzel, Kastner group (MIT)
*Charge Transport in Lead Selenide Nanocrystal Quantum Dots*
Colloidal semiconductor nanocrystals can be made to self-assemble into a
close-packed array, creating a novel material known as a nanocrystal solid.
In particular, PbSe nanocrystal solids have garnered much attention for
their application in solar cells and as tunable infrared photodetectors. We
are interested in understanding the nature of charge transport through PbSe
nanocrystals because it is necessary for their application in optoelectronic
devices and to better understand this novel material. We perform electronic
transport measurements on a PbSe nanocrystal solid, which serves as the
channel of a field-effect transistor. We find that the conduction is
strongly dependent on both temperature and applied field and that this can
be described by a model of hopping between localized states. The activation
energy to conduction is attributed to both the energy to generate charge
carriers and to disorder. From the field effect data, we extract a density
of states, which is consistent with predicted values, thereby validating our
model. We also extract a value for the Thomas-Fermi length from our data.
Cheers,
-A
--
Alejandro Perdomo-Ortiz
Ph.D. Candidate in Chemical Physics.
Harvard University
12 Oxford St #482, Cambridge, MA, 02138.
perdomo(a)fas.harvard.edu
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