Bi4 I4

Bi₄I₄ is a bismuth iodide compound belonging to the halide perovskite family of semiconductors, characterized by a layered crystal structure that emerged from research into lead-free alternatives for optoelectronic applications. This material is primarily investigated in research settings for photovoltaic devices, photodetectors, and light-emitting applications, where its reduced toxicity compared to lead halide perovskites and tunable band gap make it a candidate for next-generation solar cells and imaging sensors. Its layered structure offers potential advantages in stability and ion migration suppression, though it remains largely in the development phase rather than established in high-volume commercial production.