▎ 摘　　要

Modulating the electronic property of graphene by doping is essential for its device and circuit applications. Unfortunately, controllable p- and n-type doping in top-gated graphene field effect transistor (GFET) is reported. Here, the O-3-based atomic layer deposited Al(2)O(3)layer as top gate dielectric is chosen. The epoxide functional group formed in the O(3)process serves as effective interface trap sites. As the sweeping range of top gate voltage increases, the Dirac point position of GFET moves from positive voltage to negative voltage. The shift of the Dirac point voltage indicates the doping transition of graphene from p-type to n-type. The gate voltage dependent doping can be attributed to the charge exchange between graphene and interface trap sites. Furthermore, a trap-dependent charge model is proposed to explain the transport mechanism in the doping process. This approach is promising to produce the complementary p- and n-type top-gated GFET for multiple applications.