Abstract

Mixed-halide wide-band gap perovskites are attractive for space power due to their high open-circuit voltages and compatibility with tandem device architectures, but their response to combined orbital stressors remains under-explored. Here, we study 1.86 eV band gap all-inorganic CsPbI2Br solar cells across a space-relevant thermal window of -80°C to +100°C before and after 1.0 M eV proton irradiation. n-i-p devices exhibit notable radiation tolerance retaining approximately 60% of initial power conversion efficiency (PCE) upon irradiation with a fluence of 5 × 10^13 cm^−2. Temperature-dependent hyperspectral photoluminescence imaging and spectroscopy uncover a reversible low-temperature emissive heterogeneity in the perovskite absorber, manifested by bright, blue-shifted emission near 1.89 eV that vanishes upon warming toward room temperature, where the emission returns near 1.86 eV . Proton irradiation is found to enhance this heterogeneity. Simultaneous temperature-dependent current-voltage measurements reveal that warming modestly decreases open-circuit voltage while improving fill-factor because of decreased series resistance, highlighting a decoupling between radiative behavior and charge extraction. These observations are consistent with formation of localized regions upon cooling, likely due to phase segregation, that protect charge carriers improving radiative recombination. These results highlight that a combination of proton irradiation and cryogenic temperatures, for example, under eclipse during orbit, could cause severe carrier collection bottlenecks which should be further explored for space power.

Publication Date

8-14-2026

Document Type

Thesis

Student Type

Graduate

Degree Name

Materials Science and Engineering (MS)

Department, Program, or Center

Chemistry and Materials Science, School of

College

College of Science

Advisor

Ahmad Kirmani

Advisor/Committee Member

Pratik Dholabhai

Advisor/Committee Member

Seth Hubbard

Comments

This thesis has been embargoed. The full-text will be available on or around 8/9/2027.

Campus

RIT – Main Campus

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