Damage of high energy electron irradiation in triple junction GaAs solar cells

This study investigates the damage mechanisms of triple-junction GaAs solar cells under 10 MeV high-energy electron irradiation, addressing limitations of previous low-energy (e.g., 1 MeV) electron studies. Experimental results show that with increasing electron fluence, the electrical performance degrades significantly, with open-circuit voltage decreasing more markedly than short-circuit current. Combined CASINO and TCAD simulations reveal higher non-ionizing energy deposition and more severe displacement damage in the GaAs middle subcell. Analysis of recombination rates and energy band structure indicates an evolution of defect types from simple point defects to complex clusters under high-energy irradiation, leading to increase in recombination rate and severe band distortion. These findings provide deeper insights into the damage mechanism of high-energy electrons and lay a theoretical foundation for radiation-hardened design and lifetime assessment of space solar cells.