Performance degradation of crystalline silicon solar cells under bremsstrahlung exposure

Abstract

This study investigates the degradation of crystalline silicon (c-Si) solar cells under high-energy polyenergetic Bremsstrahlung radiation, relevant to space and high-radiation terrestrial environments. Cells were irradiated with doses up to 900 Gy using a clinical linear accelerator (cLINAC). Results demonstrate significant dose-dependent performance loss, with the power conversion efficiency (eta) decreasing by approximately 7.6 % at the highest dose of 900 Gy. This degradation was driven mainly by reduced short-circuit current density (J sc ) and increased recombination. External quantum efficiency (EQE) measurements confirmed substantial losses at longer wavelengths, indicating bulk defect generation. Capacitance and conductance analyses revealed the accumulation of deep-level traps and interface states, further elucidating the degradation mechanisms. These findings highlight the vulnerability of c-Si solar cells to Bremsstrahlung exposure and provide critical insights for developing radiation-hardened photovoltaic technologies.