Performance Evolution of CsPbI2Br Perovskite Solar Cells under Space-Equivalent Stressors

Abstract

This study investigates the suitability of all-inorganic halide perovskites of CsPbI2Br for space applications with an emphasis on their thermal stability under the simulated Low Earth Orbit (LEO) space conditions. The substrate pre-heating is found to play a critical role in obtaining ambient stable CsPbI2Br perovskite solar cells. The in-situ photovoltaic properties of the CsPbI2Br solar cells over a broad temperature range (+150 °C to −150 °C) and under combined stressors such as heat, vacuum, and AM0-like illumination were systematically investigated for both glass/ITO and fused silica/ITO substrates. The extent of performance loss and recovery is found to be strongly determined by the choice of substrates, with the fused silica/ITO-based devices showing relatively better performance recovery than the glass/ITO-based devices, after 24h. Microstructural analysis of partial device heterostructures shows that CsPbI2Br films on fused silica retain their crystalline phase, preferred orientation, and optical absorption even under extreme temperature fluctuations, indicating better thermal compatibility. Overall, this study highlights the significance of substrate engineering in enhancing the durability of CsPbI2Br perovskite solar cells for space applications.