Gate-tunable rectification inversion and photovoltaic detection in graphene/WSe2 heterostructures

We studied electrical transport properties including gate-tunable rectification inversion and polarity inversion, in atomically thin graphene/WSe2 heterojunctions. Such engrossing characteristics are attributed to the gate tunable mismatch of Fermi levels of graphene and WSe2. Also, such atomically thin heterostructure shows excellent performances on photodetection. The responsivity of 66.2 mA W-1 (without bias voltage) and 350 A W-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) cm Hz(1/2)/W, and fast response time of 30 mu s. Our study reveals that vertical stacking of 2D materials has great potential for multifunctional electronic and optoelectronic device applications in the future. Published by AIP Publishing.