Emerging Bi‐Based Multicationic Ternary Chalcogenides as Promising Photoabsorbers for Solar Cells

Bismuth‐based multicationic chalcogenide solar cells of class ABiX 2 (A–Ag, Cu; X–S, Se) have attracted substantial interest within the photovoltaic research community mainly due to their nontoxic nature and rising power conversion efficiencies. Although a good amount of research on these materials is underway, it calls for an intense and comprehensive approach to address the poor performance (PCE 10%) compared to its reported theoretical efficiency of 29%. Hence a review in this direction to address various unexplored concerns of these materials particularly, the defects and unfavorable band positions that give rise to enormous nonradiative recombinations, leading to major voltage losses in these devices is necessary. The article also discusses the structural and electronic properties, deposition techniques, device optimization strategies, impact of grain size, interface engineering, cationic disorder, transport layers, and light‐harvesting techniques that may be required to enhance the device performance. Additionally, a comprehensive analysis of stability and cost considerations of the emerging AgBiS 2 solar devices is conducted to unveil their real‐time applications in comparison to current state‐of‐the‐art devices.