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SSL Seminar Series 2002 No.7
Combined talks (two speakers)
Date: November 22, 2002
Time: 5:00-6:00pm
Venue: Physics Conference Room (Blk S13 M01-15)
Speaker I: Mr. Md. Abdul Kader Zilani
Title: STM studies of large molecules on surfaces for molecular
electronic applications
Abstract:
Molecular devices with novel quantum properties are potentially
the building block of future nanoscale electronic devices. In this
work, we will study the electronic properties of self-assembled
organic molecules, as well as variation of electronic properties
under the influence of a particular substrate. In addition, we will
investigate the molecule-induced surface reconstructions, and study
the controlled-assembly and manipulation of organic molecules on
different substrates to build specific nanostructures. Fullerenes
represent a unique structure of cage molecules with a wide range
of sizes, shapes and molecular weights. C60 makes strong bond with
Si surfaces due to its large number of dangling bonds compared with
GaAs and other surfaces. Currently we are studying the interaction
of C60 with passivated-Si surfaces and on the effect of adsorbates
to modify C60 layers. The study of self-assembly on passivated surfaces
and also passivation effect of C60 monolayer and multilayer are
important in term of molecular ordering, bonding and conductivity
of C60 films. Next part of our research consists of controlled fabrication
of nanostructure and study of electrical properties of organic molecules
such as (C60 and C70) buckyballs. We will grow fullerene-based nanostructures
on Si surface using oxygen as a mask. We want to grow nano-wire
of few molecular widths within the window of etched oxidized Si
surface.
Speaker II: Mr. Mayandi Jeyanthinath
Title: STM Studies of growth and Ordering in Ge/Si(100) Multi-layer
Quantum Dots
Abstract:
Growth and ordering of multi-layer Quantum dots (QDs) is an important
field, in the development of nano and optoelectronic devices, due
to their novel properties. The growth conditions of ordered and
uniform size multi-layer QDs have to be investigated. To study the
growth conditions, we will use an in situ ultrahigh vacuum (UHV)
scanning tunneling microscope (STM). Here we present the key problems
and explain how we will carry out the study of the atomic processes
of the multi-layer QDs growth, to reveal the roles of the spacer
layers, surface reconstruction, kinetic roughening, intermixing,
temperature and segregation. Based on these studies, we can find
an optimal growth condition for growing organized multi-layer QDs.
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