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.