Charging/discharging test to arraying structure of IMM3J solar cell

Inverted metamorphic triple-junction (IMM3J) thin-film solar cells and cell array sheets with IMM3J thin-film cells have been developed at JAXA as next-generation, high-efficiency space solar cells. Charging/discharging tests on the cell array sheets with the IMM3J cells were performed to resolve concerns about a potential increase in damage to the cells due to their thin-film structure. Two kinds of sheet structures with these cells were examined and compared with a conventional CIC structure. The threshold of the differential voltage for the discharge of the sheets was found to be higher than that of the CIC structures. The degradation mode of the IMM3J cells in the CIC structure was cell edge leaks.