Radiation tolerance analysis of space solar cells under increased irradiance conditions

Abstract In this study, we obtained the electrical performance of concentrator photovoltaics (CPV) using InGaP/GaAs/Ge triple-junction solar cells before and after high-energy particle irradiation to examine the effects of solar concentration on radiation tolerance. The conversion efficiency before radiation exposure increased in proportion to the received solar irradiance mainly because of the solar concentration effect of the open-circuit voltage ( V oc ). Additionally, our experimental results revealed that the solar concentration effect of V oc was enhanced after radiation exposure, which mitigated V oc degradation. To investigate the solar concentration effect on V oc in detail, the recombination current dependencies of the external luminescence efficiency ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>η</mml:mi> <mml:mi>ext</mml:mi> </mml:msub> </mml:math> ) of InGaP and GaAs single-junction (1J) cells were measured before and after radiation exposure. It was found that the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>η</mml:mi> <mml:mi>ext</mml:mi> </mml:msub> </mml:math> of InGaP 1J cells after radiation exposure increased with increasing recombination current, which is considered to suppress the degradation of the V oc of the CPV. These findings demonstrate the significant advantages of CPV for space applications.