Modeling the impact of proton irradiation on photoluminescence spectra of perovskite solar cells

Abstract This study presents a comprehensive modeling approach to assess the impact of proton-irradiation on the photoluminescence (PL) response and current–voltage (JV) characteristics of CsMAFAPbI 3 /P3HT-based perovskite solar cell validated against experimental data reported in literature. Proton irradiation generates displacement damage across the cell structure most critically within the perovskite bulk where the defect density increases approximately linearly with increased fluence and decreases for high proton energies due to reduced non-ionizing energy loss (NIEL) at higher energies. To capture the optical degradation behavior, Time-Resolved PL transient (TRPL) and PL spectra were modeled using a fluence- and energy-dependent Kohlrausch model (stretched-exponential) linked with Shockley–Read–Hall (SRH) recombination. Trap-creation coefficients derived from dpa-based calculations enable a physically consistent coupling between proton energy deposition, trap accumulation, and the resulting decrease in PL lifetime, initial PL amplitude, and stretching exponent. Steady-state PL and TRPL spectra similarly exhibit intensity loss without major spectral shifts, indicating that irradiation primarily enhances nonradiative recombination rate rather than affecting the energy band levels. The current-voltage characteristics were also modeled by incorporating defect-dependent reductions in carrier mobility and lifetime showing that low-energy protons (e.g., 1 MeV) degrade the device metrics stronger than high energy/fluence protons that loss their energy in perovskite layer.