Super radiation tolerance of CIGS solar cells demonstrated in space by MDS-1 satellite

High radiation tolerance of CIGS solar cells is demonstrated in space for the first time by monitoring the performance of Cu(In,Ga)Se/sub 2/ thin-film solar cells on MDS-1 since February 2002. Short-circuit current of the CIGS cells did not degrade and open-circuit voltage of the cells degraded only about 1%. In contrast, the performance of other solar cells on the satellite, including Si and GaAs space solar cells, degraded 1 year after launch. The high recovery of radiation damage of ClGS solar cells due to thermal annealing was found from ground test. We predicted the degradation of the CIGS solar cells in space using the relative degradation coefficient, the annealing rates of Voc and Isc for protons irradiating the cells and the radiation response of the cells without thermal annealing. The results are in good agreement with flight data of the CIGS solar cells on the satellite. We were thus able to demonstrate high radiation tolerance of CIGS solar cells in space for the first time.