Niel analysis of radiation degradation parameters derived from quantum efficiency of triple-junction space solar cell

Degradation modeling of InGaP/GaAs/Ge triple-junction (3J) solar cells due to proton/electron irradiation is performed with the use of a one-dimensional optical device simulator; PC1D. By fitting external quantum efficiencies of the 3J solar cells degraded by proton/electron irradiation, the short-circuit currents (ISC) and open-circuit voltages (VOC) are simulated. The validity of this model is confirmed by comparing the results of both ISC and VOC to the experimental data. Then, the degradation level in each sub-cell is evaluated. The carrier removal rate of base layer (RC) and the damage coefficient of minority carrier diffusion length (KL) in each sub-cell are also estimated. In addition, NIEL (Non-Ionizing Energy Loss) analysis for both radiation degradation parameters RC and KL is discussed.