Broadband photodetector based on ReS₂/graphene/WSe₂heterostructure

Two-dimensional van der Waals heterostructures can combine properties of individual materials to enable high-performance photodetection. Here, a novel ReS₂/graphene/WSe₂heterostructure, prepared by dry transfer, demonstrates air-stable, high-performance, polarization-sensitive, and broadband photodetection. Dark current can be strongly suppressed by the built-in electric field of the heterostructure. The specific detectivities are up to 10¹⁰Jones and 10⁹Jones under zero and reverse bias, respectively. Response time is on the order of a millisecond. The polarization-sensitive photodetection has been observed in the heterostructure due to the low lattice symmetry of ReS₂. Broadband photoresponse from visible to infrared range has been demonstrated. A high photoresponsivity of 1.02 A W^-1is achieved for illumination at the wavelength of 785 nm. This work provides a viable approach toward future high-performance, air-stable, and polarization-sensitive broadband photodetectors.