Pyro-phototronic\nEffect Enhanced Self-Powered Photoresponse\nin Lead-Free Hybrid Perovskite

Pyro-phototronic effect (PPE) can significantly boost\nthe performance\nof hybrid perovskite (HPs) photodetectors due to the effective modulation\nof photogenerated charge carrier separations, transportation, and\nextraction. However, there are few reports on the application of PPE\nin lead-free HPs. Herein, a polar lead-free HP (1,3-BMACH)BiBr<sub>5</sub> [1,3-BMACH = 1,3-<i>bis</i>(aminomethyl)cyclohexane]\nis synthesized and realized broadband self-powered photoresponse\nfrom X-rays to near-infrared (NIR) through the PPE. Particularly,\nthis light-induced PPE in lead-free HPs breaks the limitation of the\noptical band gap, making them suitable for broadband self-powered\nphotodetection. Under 405 nm illumination, compared with a purely\nphotovoltaic system, <i>I</i><sub>photo+pyro</sub> is boosted\nby 3100%, and <i>R</i> and <i>D</i>* are both\nenhanced by 260% after coupled PPE. It is particularly interesting\nthat an obvious X-ray-induced PPE phenomenon is also observed, which\nendows (1,3-BMACH)BiBr<sub>5</sub> with a high sensitivity of 154\nμC Gy<sup>–1</sup> cm<sup>–2</sup> and a low detection\nlimit of 307 nGy s<sup>–1</sup> under the self-powered mode.\nThe implementation of light-induced PPE from X-rays to NIR in lead-free\nHPs provides a new approach for constructing environmentally friendly,\nbroadband, and self-powered optoelectronic devices in the future.