Summary: 1small 2010, X, No. XX, 1­4 © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim wileyonlinelibrary.com
Graphene
Graphene, a single-atom-thick layer of sp2
-hybridized carbon
atoms, has generated considerable excitement in the scien-
tific community due to its peculiar electronic band structure,
which leads to unusual phenomena such as the anomalous
quantum Hall effect,[1,2]
spin-resolved quantum interfer-
ence,[3]
ballistic electron transport,[4]
and bipolar supercur-
rent.[5]
However, pristine graphene is a semimetal with zero
bandgap; the local density of states at the Fermi level is zero
and conduction can only occur by the thermal excitation of
electrons.[2] This lack of an electronic bandgap is the major
obstacle limiting the utilization of graphene in nano-elec-
tronic and -photonic devices,[6,7] such as p­n junctions, tran-
sistors, photodiodes, and lasers.

Source: Ajayan, Pulickel M. - Department of Mechanical Engineering and Materials Science, Rice University

Collections: Materials Science