▎ 摘　　要

The electrical behavior of backgate graphene field effect (GFET) transistor was studied at different ambient conditions. Backgate p-channel GFET transistors were fabricated on oxidized silicon wafers by exfoliation of graphite. The carrier mobilities were determined from the measured transconductance. For all ambients investigated (N-2, Ar, and air), the graphene transistors show enhanced mobilities at elevated temperatures. This behavior can be explained by a stronger screening of scattering centers, i.e., defects in graphene and at the graphene oxide interface, with increasing temperature. For operation in air the transistors showed a higher transconductance compared to the operation in nitrogen and argon due to the strong acceptor-like behavior of gases adsorbed on the graphene surface. [GRAPHICS] Effect of temperature and ambient on the output characteristic of a backgate GFET. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim