All-Inorganic Halide Perovskite Alloy Nanowire Network Photodetectors with High Performance

Organic-inorganic hybrid lead halide perovskites have attracted much attention in the photoelectric field due to their excellent characteristics, such as a tunable band gap, simple fabrication process, and high photoelectric conversion efficiency. However, the commercialization of the perovskite-based devices still faces many challenges, one of which is the inclusion of the toxic lead. Herein, we demonstrated a two-step solution method for synthesizing tin-based perovskite nanowires (NWs) with their application in photodetectors (PDs). By changing the halide exchange time and the Sn content in the precursor, the dark current of the CsPbSn_1-(BrI_1-)₃ perovskite NW PDs increased with increasing content of tin and decreased with increasing Br concentration, and the lowest dark current with a value of 0.672 nA at 1 V was achieved for the perovskite alloy NW PDs synthesized with 0.5 mg mL^-1 SnI₂. Our optimized perovskite alloy NW PDs showed high performance with a linear dynamic range of up to 120 dB, a rising/falling time of 4.25/4.82 ms, and a detectivity of 2 × 10¹⁰ Jones. In addition, our Sn-based perovskite NW devices could maintain good performance after storing in air for 30 days. These results demonstrated good practical application for the Sn-based perovskite NW devices.