13-04-2013, 04:45 PM
Electronic Band Structure of Graphene Continued
ABSTRACT
The band structure around graphene’s bandedge (the
K point) is a pair of intersecting cones. As such, the
double gradient of the band structure in that region is
discontinuous, yielding an effective mass m! of zero at the
K point and infinity in the immediate vicinity.
The verdict is still out on the methodology to de-
termine the mobility of graphene. Measured values of
graphene mobility show that it has extremely high mo-
bilities, theoretically infinite at the Dirac points, but
that these values are limited by acoustic phonon scat-
tering [3]. Graphene has been experimentally shown to
have hole mobilities commonly in the range of 3400-4400
V/cm2s [4] and as high as 15,000 V/cm2s [5]. Current re-
search suggests that graphene mobility is limited by the
density of charged impurities within the lattice, and so
the key to increasing mobility for use in higher-frequency
electronics is to reduce the number of impurities when
building graphene components. [6]
ABSTRACT
The band structure around graphene’s bandedge (the
K point) is a pair of intersecting cones. As such, the
double gradient of the band structure in that region is
discontinuous, yielding an effective mass m! of zero at the
K point and infinity in the immediate vicinity.
The verdict is still out on the methodology to de-
termine the mobility of graphene. Measured values of
graphene mobility show that it has extremely high mo-
bilities, theoretically infinite at the Dirac points, but
that these values are limited by acoustic phonon scat-
tering [3]. Graphene has been experimentally shown to
have hole mobilities commonly in the range of 3400-4400
V/cm2s [4] and as high as 15,000 V/cm2s [5]. Current re-
search suggests that graphene mobility is limited by the
density of charged impurities within the lattice, and so
the key to increasing mobility for use in higher-frequency
electronics is to reduce the number of impurities when
building graphene components. [6]