A high performance self-driven photodetector based on a graphene/InSe/MoS2 vertical heterostructure

Hybrid van der Waals heterostructures comprising ultrathin layers of different materials and offering the possibility of novel properties and unusual charge transport characteristics have become a reality in recent years. Here, we vertically stack graphene, a transition metal dichalcogenide and a III–VI semiconductor together and report a novel self-driven photodetector based on a graphene/InSe/MoS2 heterostructure. The device shows rectifying and bipolar behavior. In the self-driven mode it exhibits high photoresponsivity (110 mA W−1), fast photo-response (less than 1 ms) and high detectivity (over 1010 Jones). It also shows ambient operational stability over one month of operation and nearly uniform photocurrent distribution because of the efficient electron–hole pair separation arising from the large built-in potential at the interface of MoS2 and InSe. Our graphene/InSe/MoS2 heterostructure holds promise for novel self-driven optoelectronics based on III–VI/transition metal dichalcogenide heterojunctions.