Gate-tunable rectification inversion and photovoltaic detection in graphene/WSe_2 heterostructures

摘要

We studied electrical transport properties including gate-tunable rectification inversion and polarity inversion, in atomically thin graphene/WSe_2 heterojunctions. Such engrossing characteristics are attributed to the gate tunable mismatch of Fermi levels of graphene and WSe_2. Also, such atomically thin heterostructure shows excellent performances on photodetection. The responsivity of 66.2mAW~(-1) (without bias voltage) and 350AW~(-1) (with 1V bias voltage) can be reached. What is more, the devices show great external quantum efficiency of 800%, high detectivity of 10~(13)cmHz~(1/2)/W, and fast response time of 30 μs. Our study reveals that vertical stacking of 2D materials has great potential for multifunctional electronic and optoelectronic device applications in the future.