Ultrahigh Photoresponsive Device Based on ReS2 /Graphene Heterostructure.

Heterostructures that combine graphene and transition metal dichalcogenides, such as MoS2 , MoTe2 , and WS2 , have attracted attention due to their high performances in optoelectronic devices compared to homogeneous systems. Here, a photodevice based on a hybrid van der Waals heterostructure of rhenium disulfide (ReS2 ) and graphene is fabricated using the stacking method. The device presents a remarkable ultrahigh photoresponsivity of 7 × 105 A W-1 and a detectivity of 1.9 × 1013 Jones, along with a fast response time of less than 30 ms. Tremendous photocurrents are generated in the heterostructure due to the direct bandgap, high quantum efficiency, and strong light absorption by the multilayer ReS2 and the high carrier mobility of graphene. The ReS2 /graphene heterostructured device displays a high photocurrent under the applied gate voltages due to the photogating effect induced by the junction between graphene and ReS2 . The ReS2 /graphene heterostructure may find promising applications in future optoelectronic devices, providing a high sensitivity, flexibility, and transparency.