High energy irradiation properties of CdTe/CdS solar cells

The irradiation hardness of CdTe solar cells was investigated for extremely high fluence of protons (up to 10¹⁴ cm^-2) and electrons (up to 10¹⁸ cm^-2) since the degradation onset occurs at very high fluences. One general degradation characteristic for CdTe cells was calculated using a damage dose formulation, allowing a comprehensive comparison with other cell technologies. CdTe cells show an excellent radiation stability, superior to monocrystalline cells and also slightly superior to other thin film cells. Changes in the cell parameters are quantitatively correlated to recombination centres. For proton irradiation, a passivation of recombination centres at low and medium fluences is observed causing even an increases the efficiency. The damage recovery of CdTe cells shows an exponential time dependence.