Managing Lead Leakage in Efficient Perovskite Solar Cells with Phosphate Interlayers

Abstract Lead leakage from perovskite solar cells (PSCs) leads to device failure and environment contamination. Here, these issues are solved with a sodium phosphate (Na 3 PO 4 )‐modified tin(IV) dioxide (SnO 2 ) layer that simultaneously boosts the device performance and captures most of dissolved lead in water. Phosphate incorporation improves charge transfers and passivates the buried perovskite interface, leading to highly improved device efficiency up to 23% with negligible hysteresis. More importantly, the phosphatized SnO 2 layer shows high lead‐adsorption capacity with a sequestration efficiency of 79.6% due to the numerous anchor sites of oxygen lone pairs, converting dissolved lead into insoluble compounds in water. This study presents a facile protocol of efficient and sustainable perovskite photovoltaics upon future commercialization.