A spectrally resolved degradation framework for perovskite solar cells under orbit-specific space stressors

Perovskite solar cells (PSCs) are promising candidates for space photovoltaics because of their high specific power, tunable optoelectronic properties, and compatibility with lightweight and flexible device architectures. Their degradation under space operation, however, cannot be captured adequately by coarse orbit-class averages alone, since photovoltaic stability depends on the temporal structure of exposure, the spectral content of the radiation environment, and the energy-dependent filtering introduced by shielding. Here, we present a screening-level, semi-empirical degradation framework for PSCs under orbit-specific space stressors that combines analytical orbital propagation, time-resolved environmental modulation, energy-dependent particle shielding, and a five-channel effective damage-source model within a unified source-term architecture. The framework separates ionizing-like and displacement-like effective source terms, converts transmitted proton and electron spectra into effective time-dependent degradation sources, and maps accumulated damage to reduced-order photovoltaic observables, including J s c , V o c , fill factor, and power conversion efficiency. Representative simulations for LEO, MEO, GEO, and HEO conditions show that moving from a classical scalar description to a spectrally resolved orbit-aware treatment changes both the magnitude of estimated degradation and the largest modelled source-term contributions in an orbit-dependent manner. After one year, absorber-level retained PCE values are 73.9% for LEO-ISS, 86.0% for MEO-Navigation, 91.6% for GEO-Comms, and 91.3% for HEO-Molniya under the nominal parameterization. External benchmark cases based on SPENVIS-like proton and electron spectra support the framework as a comparative screening tool. Overall, the proposed framework provides a computationally efficient but physically enriched basis for comparative degradation assessment, uncertainty analysis, and early reliability-oriented design studies of perovskite photovoltaics for space applications, while remaining conditional on stack-specific calibration rather than constituting a qualification-level lifetime model.