UC Merced

Metal halide perovskites (MHPs) have garnered significant interest as semiconductors for optoelectronic devices like solar cells in the past 15 years due to their defect tolerant crystal structure, tunable bandgap, and impressive photovoltaic performance. This dissertation will examine the viability of MHP-based photovoltaics for operation in the harsh low Earth orbit (LEO) environment around the International Space Station (ISS) through a combination of ground-based experiments and analysis of samples exposed to actual LEO conditions. To evaluate the resiliency of MHPs in space, prototype thin films of the perovskite methylammonium lead iodide (MAPI) were flown on multiple Materials International Space Station Experiment (MISSE) missions mounted outside the ISS. Among these was the first perovskite device to orbit the Earth, doing so nearly 4800 times and demonstrating MHPs could survive for 10 months in LEO. Optical analysis like photoluminescence spectroscopy will be discussed heavily throughout this work, as most samples were electrically isolated and fully encased in glass. To further explore the effects of high-energy particle radiation in LEO, unencapsulated MAPI films were subjected to controlled proton and neutron irradiation on Earth. While neutron exposure caused no changes, proton fluences above 1013 cm−2 led to photodarkening, spectral blueshift, and reduced charge carrier lifetimes. Such proton fluences are orders of magnitude greater than those experienced over a decade in LEO, demonstrating MHP resilience to particle damage. Finally, this thesis will examine the effects of the LEO environment on complete MHP solar cell devices of different architectures. Through advanced spectroscopy and microscopy, the fundamental photophysics of MHPs subjected to these extreme stressors will be revealed. Overall, the cells returned with localized MHP damage due to top contact (Ag or Al) migration, though the perovskite remained intact outside of these regions.