CHEM01200604009 Sreejith Kaniyankandy - Homi Bhabha ...

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CHAPTER 6
Charge Separation in CdTe Decorated Graphene
6.1. Introduction
Graphene is a 2-D array consisting of sp 2 hybridized carbon atoms in a honeycomb lattice.
This distinctive structure imparts graphene with a unique linear electronic dispersion near the
K-point of the Brillouin zone [6.1] which leads to relativistic velocity of ~ 10 6 m/s and
mobility of ~15000 cm 2 /Vs for the electrons [6.2]. These unique properties are ideally suited
for application in fast electronic devices like transistors, diodes and oscillators [6.3]. Apart
from these applications, graphene has been exploited for verifying table top quantum
electrodynamics experiments due to its unique electronic structure. Previously, several
groups have verified a number of exotic behaviors like the observation of room temperature
Quantum Hall Effect [6.4], Klein paradox [6.5] etc. These applications and interesting novel
properties of graphene have given impetus to their synthesis by different routes. The first
report on synthesis of graphene was by Geim et al [6.4] who produced graphene by
micromechanical cleavage from highly oriented pyrolitic graphite (HOPG) using a scotch
tape [6.2]. Graphene prepared by micromechanical cleavage was used to verify several novel
attributes of graphene like observation of Klein paradox, Quantum Hall Effect, high mobility
etc. at room temperature. However, from the application point of view, the scotch tape
method is not very conducive due to non scalability.