Fig. 1. （a）Schematic diagram of SnS₂/InSe heterostructure.（b）Raman spectrum of the single SnS₂，single InSe and their overlapped regions.（c）Height measurement maps of SnS₂ and InSe flakes in AFM，with insets showing the topographic views of SnS₂/InSe devices.（d）The SEM image of the SnS₂/InSe device.（e）HRTEM image，scale bar：1 μm.（f）EDS image of each layer element.

Fig. 2. (a) Schematic diagram of the device measure setup. (b) I_ds-V_ds output characteristic curves for different gate voltages under dark conditions (The inset was the output characteristic curves of SnS₂). (c) I_ds-V_g transfer characteristic curves for different source-drain voltage under dark conditions. (d) The logarithmic curves of I_ds-V_g when the source-drain voltage (V_ds) is 5 V. (e) Output characteristic curves for different incident optical power densities under 365 nm illumination (V_g=0 V). (f) Transfer characteristic curves for different incident optical power densities under 365 nm illumination (V_ds=5 V).

Fig. 3. SnS₂/InSe heterojunction photodetector under 365 nm illumination.（a）I_ph as a function of incident optical power density and gate voltage（V_ds=5 V）.（b）Responsivity as a function of gate voltage for different incident optical power densities.（c）Detectivity and noise equivalent power as functions of incident optical power density.（d）External quantum efficiency as a function of incident optical power density.

Fig. 4. （a）Optical switching characteristic curve under 365nm illumination.（b）Rise and fall time of photocurrent under 365nm illumination.

Fig. 5. (a) Optical switching characteristics under different incident light wavelength irradiation. (b) 2D images of responsivity as a function of gate voltage and incident light wavelength. (c) Detectivity and noise equivalent power as a function of incident light wavelength. (d) External quantum efficiency as a function of incident light wavelength.