Graphene-GaAs/Al_xGa_(1-x)As heterostructure dual-function field-effect transistor

摘要

We have integrated chemical vapor-deposited graphene and GaAs/Al_xGa_(1-x)As heterostructure into a hybrid field effect transistor (FET). Depending on the operation scheme, graphene can be utilized either as a gate electrode for a GaAs-based high electron mobility transistor (HEMT) or as a channel material gated by two dimensional electron gas (2DEG) formed in the interface of a heterojunction. Our studies reveal that 2DEG can function as an effective back-electrode to tune the ambipolar effect of graphene. The performance of graphene FET (GFET) is limited by the interface band bending of the heterojunction associated with the gating voltages and the intrinsic surface morphology of GaAs substrate. Our results bode a way to implement HEMT/GEFT-based bi-FET integrated circuits.