Radiation resistance of InGaP/GaAs dual-junction thin-film space solar cell

Thinned III-V multi-junction solar cells can realize the advantages of being high-efficiency and light-weight, as such these cells meets the requirement for higher W/kg and W/m³ solar panels. Here we report the development results of a thin-film InGaP/GaAs dual-junction (TF2J) solar cell. In this paper, we study the radiation resistance of the TF2J cells with efficiency of 20-23% under AM0, 1sun at 25°C. The cells were subjected to proton irradiation with an energy range of 100keV-10MeV. The results were compared with the radiation resistance of a conventional InGaP/GaAs/Ge triple-junction (3J) cell. In the proton energy range of 200-400keV, radiation resistance of the TF2J cell is superior to that of the 3J cell. Particularly, the Isc of the TF2J cell is significantly higher than that of the 3J cell after exposure to 380keV and 1MeV protons, which results in higher remaining factor of Pmax for the TF2J cell. In addition, Voc of the cells after the irradiations are almost equivalent, even though the TF2J cell is a dual-junction structure. The higher Isc of the TF2J cell after irradiation is due to higher radiation resistance of the GaAs sub-cell according to EQE comparison.