Powering the Future: Opportunities and Obstacles in Lead-Halide Inorganic Perovskite Solar Cells

Efficiency, stability, and cost are crucial considerations in the development of photovoltaic technology for commercialization. Perovskite solar cells (PSCs) are a promising third-generation photovoltaic technology due to their high efficiency and low-cost potential. However, the stability of organohalide perovskites remains a significant challenge. Inorganic perovskites, based on CsPbX_₃ (X = Br^-/I^-), have garnered attention for their excellent thermal stability and optoelectronic properties comparable to those of organohalide perovskites. Nevertheless, the development of inorganic perovskites faces several hurdles, including the need for high-temperature annealing to achieve the photoactive α-phase and their susceptibility to transitioning into the nonphotoactive δ-phase under environmental stressors, particularly moisture. These challenges impede the creation of high-efficiency, high-stability devices using low-cost, scalable manufacturing processes. This review provides a comprehensive background on the fundamental structural, physical, and optoelectronic properties of inorganic lead-halide perovskites. It discusses the latest advancements in fabricating inorganic PSCs at lower temperatures and under ambient conditions. Furthermore, it highlights the progress in state-of-the-art inorganic devices, particularly those manufactured in ambient environments and at reduced temperatures, alongside simultaneous advancements in the upscaling and stability of inorganic PSCs.