Efficient and Durable Semitransparent Perovskite Solar Cells for the Application in 4T Perovskite/c‐Si Tandem Devices

ABSTRACT Semitransparent perovskite solar cells (ST‐PSCs) are becoming increasingly important for applications such as tandem photovoltaics and building‐integrated photovoltaic technologies. A significant challenge in their fabrication is the damage caused by sputtering during the deposition of transparent conductive oxides (TCOs), which can harm exposed layers and degrade device performance. To tackle this issue, we develop an optimized fabrication strategy that incorporates a tin oxide (SnO 2 ) buffer layer, effectively protecting the sensitive layer from sputtering‐induced damage during the deposition of TCOs, specifically indium in oxide (ITO), which serves as the rear electrode. The resulting ST‐PSCs achieved a record power conversion efficiency (PCE) of 21.87%. Additionally, when integrated into a four‐terminal (4T) tandem configuration with a commercial crystalline silicon (c‐Si) bottom cell, the combined device reaches an over‐efficiency of 27.15%. Beyond efficiency, these devices exhibit remarkable operational stability, achieving a T 80 of 1600 h during continuous light soaking (ISOS‐L‐1) and maintaining performance for over 4000 h in outdoor conditions (ISOS‐O‐3) through an effective encapsulation technique.