Estimation method for radiation resistance of multi-junction solar cells using I-V characteristics of subcells

Nakamura, Tetsuya*; Imaizumi, Mitsuru*; Sugai, Mitsunobu*; Sato, Shinichiro; Oshima, Takeshi

Recently a new method was proposed that estimating the current-voltage (IV) characteristics of subcells in a multi-junction (MJ) solar cell by using electroluminescence (EL). The estimated IV characteristics of electron-irradiated MJ solar cell from the IV curve obtained from each subcell agreed well with the actual dark IV (DIV) and light IV (LIV) characteristics, except for series resistance () and shunt resistance (). of a MJ cells and of subcells can be also clarified through measurement LIV characteristics using color bias lights and circuit simulation program. In this work, we applied this method to InGaP/GaAs dual-junction (2J) solar cells irradiated with electrons. As a result, we succeeded to predict the degradation curve of maximum power of the 2J solar cell where the current-limiting subcell changes from InGaP to GaAs subcell using degradation curve of each parameter.