▎ 摘　　要

This work studies the transport properties of field effect transistors fabricated on graphene single monolayer flakes. In particular, carrier mobilities in graphene for electrons and holes as a function of the vertical electric field are presented and compared with universal mobility curves in silicon. The graphene device shows excellent transport properties, especially at low electric fields due to the lack of Coulomb scattering. At higher electric fields, the phonon scattering dominates and makes the electron mobility similar to the one in silicon. The effect of defects and traps by charged impurities in the transport properties has also been studied, and it has been shown that an initial high temperature annealing significantly improves the transport properties and stability of these devices. (c) 2010 American Vacuum Society. [DOI: 10.1116/1.3516649]