Progress in all‐dry‐processed inorganic perovskite solar cells

Abstract All‐inorganic perovskites are promising absorber materials for next‐generation perovskite solar cells (PSCs) owing to their potentially superior thermal and environmental stability compared with organic–inorganic counterparts. However, the instability of the black perovskite phase poses coupled challenges for device efficiency and durability. While noticeable progress has been made using solution process routes, its compatibility with mass production is questionable. Vapor‐phase routes, especially thermal evaporation, offer a solvent‐free pathway to highly uniform thin films with precise control over thickness, composition, and interfaces, and can be integrated into existing semiconductor toolsets. This review discusses recent progress in all‐dry‐processed inorganic PSCs, covering thermally evaporated inorganic absorbers and vacuum‐grown inorganic transport layers. First, phase behavior of Cs‐based inorganic perovskites under vacuum processing is discussed where composition, crystallite size, and surface chemistry govern access to and retention of the photoactive black framework. We then summarized various vapor deposition routes to form inorganic perovskites with desirable phase purity, morphology, and optoelectronic quality. The vacuum‐compatible additive engineering and passivation strategies are also discussed. Finally, inorganic hole and electron transport layers based on dry processes are reviewed. Collectively, this review provides insights into research directions toward efficient, scalable, and intrinsically more robust all‐dry inorganic PSCs.