Tailoring bandgap and electron affinity of spacecraft dielectrics for synergistic solar array charging and discharge suppression

As the core power source for spacecraft in orbit, the reliability of solar arrays (SAs) critically determines mission success. However, the increasingly severe spacecraft charging-discharging issue under complex space environments restricts next-generation high-voltage, high-power spacecraft. Current mitigation strategies rely largely on process-based measures such as adhesive coating, while the physical mechanisms and a material-based mitigation framework remain underexplored. We systematically investigate the roles of the bandgap and electron affinity of coverglasses in SAs during surface charging-discharging using theoretical modeling, numerical simulation, and experimental validation. Under high-energy electron irradiation, bandgap governs internal secondary electron generation, whereas electron affinity controls true secondary electron emission. Increasing both reduces surface charging potential differences and suppresses secondary electron yield, mitigating electrostatic discharge risk. This work reveals intrinsic links between material band parameters and charging-discharging dynamics, offering guidance for dielectric material selection and modification in high-power spacecraft.