Phosphorus‐Doping Enhanced Self‐Powered Photoelectric Performance of SnS2‐Based Schottky Junction Photodetectors

Abstract SnS 2 , a promising candidate for high‐performance photodetectors (PDs), encounters challenges as high dark current and poor stability in practical applications. Herein, pristine SnS 2 (P 0 SS) and phosphorus (P) doped SnS 2 single crystals (P 1 SS, P 2 SS) are synthesized and implanted into devices with an asymmetric electrode contact structure, which demonstrate self‐powered photoelectric responses. At 0 V, P‐doped SnS 2 PDs exhibit significant broadening of the response spectrum. Meanwhile, the P 2 SS device achieves the highest responsivity of 57.4 mA W −1 and specific detectivity of 1.22 × 10 11 Jones at 365 nm, and has superior long‐term cyclic stability. At 1 V, the dark current of P 2 SS is significantly lowered, and the on‐off ratio is about two orders of magnitude higher than those for the other two at 515 nm. The self‐powered phenomenon of the three PDs here is attributed to the asymmetric Schottky barriers at the two gold/SnS 2 interfaces of the source and drain electrodes. The enhanced photoelectric response of the P‐doped SnS 2 PDs can be due to the lowered conductivity and higher exciton separation efficiency by the compensation doping. This work offers a promising pathway for optimizing the optoelectronic detection capability of future portable devices.