Stability and Degradation of Metal Halide Perovskite Solar Cells Under Multiple Space Relevant Stressors

The operational stability of metal halide perovskite (MHPs) solar cells in space is influenced by various factors including launch-induced degradation, radiation exposure, high intensity photoexcitation under large temperature swings, as well as charge accumulation effects (amongst others). Here, we present a study that focuses on employing combinations of space relevant stressors to mimic the operational conditions that MHP solar cells may experience in space and under pre-launch conditions. [1] A series of MHP solar cells are assessed in terms of their stability and performance while implementing various encapsulation protocols, as well as in unencapsulated devices which are used to accelerate environmental degradation. Consistent with previous studies, the MHP devices assessed here show high radiation stability, but are much more sensitive to environmental conditions that might be experienced under the high temperature high humidity prelaunch conditions expected in the United States. Degradation is also evident under constant solar illumination at fixed biases particularly when the devices are exposed to high temperature thermal cycling implemented to mimic charge build up in MHPs in space. Additionally, initial assessments of polymer based encapsulants indicate these systems suffer decomposition due to excessive heating under high energy proton exposure. [2] While the use of space grade glass prevents parasitic low energy radiation from directly impacting the structure, there is also a loss of device performance in these architectures when exposed to high fluence proton irradiation. This is attributed to the low thermal conductivity of the glass and the generation of excessive local heat in the cover glass that negatively affects the device layers.<br/>[1] M. N. Khanal <i>et al</i>. J Phys. Energy (under review) 2024<br/>[2] M. N. Khanal <i>et al</i>. Proc. 52^nd IEEE PVSC (2024)