Prospects for Commercialization of CsPbIBr₂-Based All-Inorganic Perovskite Solar Cells: Fabrication, Stability, and Engineering Strategies

In recent times, all-inorganic perovskite (PVK) solar cells (PSCs) have attracted growing interest owing to their superior stability under temperature and light exposure relative to organic-inorganic hybrid (OIH)-PSCs. However, their commercial viability remains a distant goal because of suboptimal performance and susceptibility to humid conditions. Among all-inorganic PVKs, cesium lead iodide bromide (CsPbIBr₂) mixed-halide PVK has garnered significant attention for its improved thermal and ambient stability. Despite years of extensive research, CsPbIBr₂-based PSCs have accomplished a peak power conversion efficiency (PCE) of ≈12.5%, which is significantly lower than the Shockley-Queisser (S-Q) efficiency threshold of ≈21.54%. Although the enhanced thermal and moisture stability of CsPbIBr₂ PVK has led to notable improvements, further optimization is essential to reach PCE levels comparable to other PVKs, which often exceed 80% of the S-Q limit. This article offers a summary of the latest advancements in CsPbIBr₂-based PSCs, covering fabrication methods for CsPbIBr₂ films, strategies to enhance device stability, and advancements in improving PCE. Innovative engineering techniques, including interface, doping, solvent, and additive engineering, are emphasized as crucial for boosting the performance and stability of CsPbIBr₂-based PSCs. Of these strategies, interface engineering has demonstrated the most significant impact. Furthermore, the review explores emerging challenges and future research prospects, offering insights into cutting-edge strategies for refining the performance of CsPbIBr₂-based devices.