Advancements and prospects for eco-friendly, high-performance silver bismuth halide solar cells

The demand for lead-free alternatives to lead-halide perovskite (LHP) solar cells has prompted extensive research efforts to explore alternative materials. Silver bismuth iodide (Ag-Bi-I) absorbers have an appropriate band gap between 1.8 and 1.9 eV for solar cells and exhibit a high absorption coefficient and excellent stability under ambient conditions. However, achieving sufficient power conversion efficiency (PCE) at the lab scale. The maximum PCE reported to date for Ag-Bi-I (SBI) materials is 5.56%, a much lower PCE value than those obtained for LHP based solar cells. Various approaches have been employed to improve the properties of SBI-based solar cells, including solution engineering, additive incorporation, and cation exchange. However, trap-assisted recombination and intrinsic limitations may be the underlying factors impacting their efficiency. With an overview of previous research efforts on SBI materials, we highlight different approaches for PCE enhancement and discuss the current state of basic research on material preparation and analysis. Furthermore, this study offers insights and prospects for SBI as a material for solar energy applications.