Suppressing Dewetting in Ultrathin Metal Films via SnO_x Cladding Layer for Efficient Semitransparent Perovskite Solar Cells

Ultrathin metal films (UTMFs) are promising electrode candidates for semitransparent perovskite solar cells (St-PSCs). However, deposited UTMFs often exist in metastable or unstable states, leading to dewetting or aggregation at elevated temperatures, which compromises the stability of the St-PSCs. Here, we investigate the stability behavior of UTMFs in St-PSCs during operational conditions and discover that the solid-state dewetting of UTMFs can occur even at room temperature and atmospheric pressure. By introducing an additional tin oxide (SnO x ) cladding layer on the top of UTMFs via atomic layer deposition (ALD), the stability of UTMFs and St-PSCs is significantly improved. Our St-PSCs with UTMFs/SnO x electrodes achieve a promising power conversion efficiency (PCE) of 20.1%. Encapsulated devices retain 95% of the initial efficiency after 500 h continuous operation under 1 sun illumination.