2 research outputs found
Mobility variations in mono- and multi-layer graphene films
The electric properties of mono- and multi-layer graphene films were
systematically studied with the layer number determined by their optical
contrast. The current modulation increased monotonically with a decrease in the
layer number due to the reduction of the interlayer scattering. Carrier
mobility in the monolayer was significantly greater than that in the multilayer
due to linear dispersion relation. On the other hand, in the monolayer, carrier
transport was extremely sensitive to charged impurity density due to the
reduction in screening effect, which causes larger mobility variation.
Reduction of the charged impurity density is thus key for high mobility.Comment: 4 page
Systematic Investigation of the Intrinsic Channel Properties and Contact Resistance of Monolayer and Multilayer Graphene FET
The intrinsic channel properties of monolayer and multilayer graphene were
systematically investigated as a function of layer number by the exclusion of
contact resistance using four-probe measurements. We show that the continuous
change in normalized sheet resistivity from graphite to a bilayer graphene is
governed by one unique property, i.e., the band overlap, which markedly
increases from 1 meV for a bilayer graphene to 11 meV for eight layers and
eventually reaches 40 meV for graphite. The monolayer graphene, however, showed
a deviation in temperature dependence due to a peculiar linear dispersion.
Additionally, contact resistivity was extracted for the case of typical Cr/Au
electrodes. The observed high contact resistivity, which varies by three orders
of magnitude (from ~103 to 106 Ohm micron), might significantly mask the
outstanding performance of the monolayer graphene channel, suggesting its
importance in future research