Engineering Chemical Vapor Deposition for Lead-Free Perovskite-Inspired MA3Bi2I9 Self-Powered Photodetectors with High Performance and Stability

Lead-free perovskite-inspired materials (PIMs) have attracted great interest in optoelectronics, as they feature electronic properties similar to mainstream lead-based perovskites but are not burdened by the same toxicity issues. However, PIM photodetectors to date have not delivered efficiencies and stability on par with benchmark technologies. With a focus on methylammonium bismuth iodide (MA(3)Bi(2)I(9))-a prominent lead-free PIM-this study overcomes this challenge by growing the photoactive material through an engineered chemical vapor deposition (CVD) approach. While the commonplace one-tube (1T)-CVD approach delivers films with disconnected grains and large pinholes, a two-tube (2T)-CVD approach is developed that enables the growth of smoother films with superior, compact morphology. The considerable optoelectronic potential of 2T-CVD MA(3)Bi(2)I(9) films is demonstrated by realizing high-performance self-powered photodetectors, which deliver a responsivity and specific detectivity as high as 0.28 A W-1 and 8.8 x 10(12) Jones, respectively, under UV illumination-i.e., approximately twice as large as the 1T-CVD counterparts. Further, nonencapsulated 2T-CVD devices exhibit considerable long-term moisture stability, with an attenuation of their photoresponse of <= 3% over 100 days. These results demonstrate that 2T-CVD offers a promising platform that can catalyze the development of high-performance lead-free perovskite-inspired optoelectronics.

Automated summary

Lead-free perovskite-inspired materials (PIMs) have shown promising electronic properties without the toxicity issues of lead-based perovskites, but have not matched the efficiency and stability of benchmark technologies in photodetectors. This study demonstrates the potential of high-performance self-powered photodetectors using a two-tube chemical vapor deposition (2T-CVD) approach to grow smoother and more compact photoactive films of methylammonium bismuth iodide (MA(3)Bi(2)I(9)). The results show that 2T-CVD offers a promising platform for the development of high-performance lead-free perovskite-inspired optoelectronics with improved efficiency and stability.