Evaluation of the electrical characteristics of III-V compounds solar cells irradiated with protons at low temperature

Triple-junction (3J) solar cells designed for space applications were irradiated with protons at 10 MeV at 175 K. The electrical performance of the 3J-junction solar cells was measured in situ under AM0 illumination at low temperature. The electrical performance of the solar cells decreases with increasing proton fluence, and at a proton fluence of 1×10¹³/cm², I_sc and V_oc become approximately 87 and 80% of the values before irradiation, respectively, indicating higher radiation resistance compared to Si solar cells. No significant difference in the degradation behavior of the electrical performance is observed between low temperature and RT irradiations. The influences of light illumination and current injection on the electrical characteristics were studied at low temperatures to minimize thermal annealing effect. For light illumination, the change in the electrical characteristics of 3J solar cells under AM0 illumination was investigated at 175 K. The electrical performance does not change by AM0 illumination for 370 min. On the other hand, using current injection at 155 K, a significant recovery of the electrical performance of 3J solar cells irradiated with protons is observed. At current injection times of 4500 sec, a 10 % recovery of I_sc and V_oc compared to the values after irradiation at 3×10¹³/cm² is shown.