Comparative study on degradation characteristics of component subcells in IMM triple-junction solar cells irradiated with high-energy electrons and protons

The radiation response of single-junction InGaP, GaAs and InGaAs cells with different indium content (20 and 30%), which are component subcells of inverted metamorphic triple-junction (IMM3J) solar cells, were prepared and irradiated with 10 MeV protons and 1 MeV electrons. Degradation characteristics, such as the change in the LIV, DIV, and EQE of the four types of cells were compared and analyzed, and the difference in the radiation response to protons and electrons, especially for InGaAs cells, was investigated. The results indicate that the InGaP cell has the highest radiation resistance to both electrons and protons, as expected. However, compared with InGaP and GaAs cells, the electron radiation resistance for the photocurrent of the InGaAs cells is remarkably low, while the radiation resistance for the photovoltage of the InGaAs cells is comparable to that of the other two cells.