High-performance near-infrared Schottky-photodetector based graphene/In₂S₃ van der Waals heterostructures

Two-dimensional (2D) β-In₂S₃ is a natural defective n-type semiconductor attracting considerable interest for its excellent photoelectronic performance. However, β-In₂S₃ based photodetectors exhibited a weak near-infrared photoresponse compared to visible wavelength in past reports. In this work, high-quality 2D β-In₂S₃ nanosheets were prepared by a space-confined chemical vapor deposition (CVD) method. Graphene/In₂S₃ van der Waals heterostructures were constructed to realize an enhanced near-infrared photodetection performance by a series of transfer processes. The photodetectors based on graphene/In₂S₃ van der Waals heterostructures through junction carrier separation exhibited a better infrared performance of high photoresponsivity (R _light) of 0.49 mA W^-1, external quantum efficiency (EQE) of 0.07%, and detectivity (D*) of 3.05 × 10⁷ jones using an 808 nm laser.