Radiation-resilient monolithic wide-bandgap perovskite/p-type heterojunction silicon tandem solar cells for space photovoltaics

Perovskite/silicon tandem solar cells (TSCs) are attractive candidates for efficient, low-cost space photovoltaics, but radiation tolerance and operational stability limit deployment. Here, a monolithic tandem architecture integrating a stabilized 1.72–electron volt wide-bandgap perovskite top cell with a radiation-hardened p-type heterojunction silicon bottom cell is reported. The perovskite absorber is stabilized by a multifunctional ionic liquid additive, which enhances crystallinity, suppresses phase segregation, and improves thermal and photostability, resulting in a power conversion efficiency of 24.0% and a certified value of 23.58%. The resulting TSCs exhibit a certified zero air mass efficiency of 27.49% (12.56 square centimeters). Under 1 mega–electron volt electron irradiation at 1 × 10 14 electrons per square centimeter, the TSC retains nearly 80% of its initial performance, whereas under 150 kilo–electron volt proton irradiation at 1 × 10 12 protons per square centimeter, it retains 93% of its initial performance, accompanied by a recoverable response. A high-altitude balloon campaign further records a stable power output of up to 387.4 milliwatt at ∼30-kilometer altitude. This work demonstrates a viable pathway for next-generation space photovoltaics.