Lead-free Cs3Bi2I9 perovskite hexagonal microplates: A promising material solution-processed for ultraviolet self-powered photodetectors

In recent times, hybrid organic-inorganic lead halide perovskites have garnered significant attention in the realm of optoelectronic devices. Metal halide perovskites are extensively researched for photodetection due to their exceptional optical and electrical properties. However, the toxicity of lead and the unstable nature of organic components are limiting its potential. Lead-free perovskites, on the other hand, have low toxicity and are being explored as a promising material for photodetector applications. However, achieving self-powered perovskite photodetectors with high photoresponse, broad spectral sensitivity, and long-term stability remains challenging Among them, Cs3Bi2I9 perovskites have emerged as standout, garnering attention for their environmentally friendly nature, impressive stability, and heightened photosensitivity. Herein, FTO/ Al-doped ZnO (AZO)/ Cs3Bi2I9/P3HT/C self-powered ultra-violet (UV) photodetector. This device demonstrated outstanding selfpowered photodetection capabilities with a photoresponsivity of 29 mA/W, a specific detectivity of 1.05x1011 Jones, and an impressive response rise and decay time of 90 ms /140 ms. Furthermore, the PDs device can function as a bias-based UV photodetector.