▎ 摘　　要

The metal/graphene contacts play a very important role in the performance of graphene-based devices. We report here a unique observation of current-induced doping in graphene transistors. The charge carrier type and the concentration in graphene can be manipulated by the current flowing through the graphene device, arising from the asymmetrical metal/graphene barriers between the source and drain electrodes and the accompanied current crowding effect. (C) 2014 AIP Publishing LLC.