Prospect for Bismuth/Antimony Chalcohalides-Based Solar Cells

Inorganic-organic hybrid lead halide perovskites are emerging optoelectronic materials for solar cell application. However, the toxicity concerns and poor stability largely hamper their practical applications. For these reasons, the search for "perovskite-inspired" alternatives, having the same advantages but overcoming the drawbacks of the lead-based one, has become an important sector in the field. Among the candidates, Bi3+ and Sb3+ containing materials are of great interest, due to their electronic structures resembling the Pb2+. Bismuth/antimony chalcohalides have been known for a long time as the potential absorber in photovoltaics, even if their performances are still low. Interestingly, pnictogen chalcohalides can be the stepping stone toward numerous quaternary compounds, including some perovskite structures. The understanding of the fundamental properties and the current limitations of both the starting ternary compounds and the final quaternary materials can allow the achievement of improved photovoltaic absorbers, stable, and efficient. In this review, the fundamental properties and device performances of many ternary pnictogen chalcohalides and the derived quaternary compounds are summarized, focusing on the different preparation strategies. Antimony/bismuth chalcohalides as light harvesting materials have attracted much attention due to their natural abundance and great photovoltaic properties. However, because of the relatively recent emergence of this class of materials, it remains inadequate about summaries of related advances. To analyze the advantages and properties of antimony/bismuth-based chalcohalide materials, such as the crystal structure, band gap, effective mass, electrical properties, and fabrication process can maximize its potential and benefit others' studies in the future.image