Tin Oxide Electron‐Selective Layers for Efficient, Stable, and Scalable Perovskite Solar Cells

Perovskite solar cells (PSCs) have become a promising photovoltaic (PV) technology, where the evolution of electron-selective layers (ESLs), an integral part any PV device, has played distinctive role to their progress. To date, mesoporous titanium dioxide (TiO2)/compact TiO2 stack been among most used ESLs in state-of-the-art PSCs. However, this material requires high-temperature sintering and may induce hysteresis under operational conditions, raising concerns about its use toward commercialization. Recently, tin oxide (SnO2) emerged as attractive alternative ESL, thanks wide bandgap, high optical transmission, carrier mobility, suitable band alignment with perovskites, decent chemical stability. Additionally, low-temperature processability enables compatibility temperature-sensitive substrates, thus flexible devices tandem cells. Here, notable developments SnO2 perovskite-relevant ESL are reviewed emphasis placed on various fabrication methods interfacial passivation routes champion Further, techno-economic analysis materials for large-scale deployment, together processing-toxicology assessment, is presented. Finally, perspective how can be instrumental successful module perovskite-based cell manufacturing provided.