Advancing wide-band-gap perovskite solar cells via vapor-phase deposition

Wide-band-gap perovskite solar cells (WBG PSCs) hold significant optoelectronic potential, with applications spanning building-integrated photovoltaics, large-area modules, and tandem solar cells. Vapor-phase deposition, leveraging its unique solvent-free processing, provides an ideal platform to address critical WBG perovskite challenges, including halide segregation, phase instability, and defect control. This review critically assesses the vapor-phase technology landscape for WBG perovskites. It first dissects fundamental physicochemical challenges in vacuum environments: mixed-halide lattice thermodynamic metastability, precursor sublimation kinetic mismatch, and complex organic cation volatility. It then systematically evaluates advanced deposition methodologies, ranging from sequential evaporation to hybrid vapor-solution routes, alongside optimization strategies spanning nucleation thermodynamics, bulk defect management, and interface energy alignment. It further examines the translation of material innovations into functional devices, highlighting vapor deposition's advantages in semitransparent cells, scalable modules, and high-efficiency perovskite/silicon tandem cells, before outlining key challenges and future directions to guide both fundamental research and industrial-scale development.