Figure 9.

a) Schematic view of a SnS₂ photodetector with 450 nm laser for illumination. Inset shows the optical image of a device. Reproduced with permission.149 b) Transfer curves at light illumination. Inset: schematic diagram of the phototransistor. c) Photoresponse ratio as a function of V _g. (b,c) Reproduced with permission.118 d,e) Schematic diagrams of two kinds of single micrometer sized GeSe based photodetector with top‐contact and bottom‐up‐contact. Reproduced with permission.94 f) Gate tunable output characteristics of SnS₂/SnS vertical heterostructures, inset: device schematic. g) Dark I–V curve and I _ph–V curve under 3.06 eV light illumination with a power of 3.2 μW. Left inset: photovoltaic I–V curves, showing the open‐circuit voltage of 0.21 V. Right inset: corresponding band diagram of the heterojunctions. f,g) Reproduced with permission.130 2015, American Chemical Society. h,i) Schematic of the SnS_2–xSe_x based photodetectors, and 3D view of photoresponsivity mapping of few‐layered SnS_2–xSe_x phototransistor. Reproduced with permission.197 2016, American Chemical Society. j,k) Schematic diagram for epitaxial growth of Pb_1–xSn_xSe nanoplates on few‐layer BN, and mid‐infrared detection of Pb_1–xSn_xSe nanoplates at 1.7–2.0 μm. Reproduced with permission.107