Light-induced Degradation of Silicon Solar Cells with Aluminiumoxide Passivated Rear Side

Abstract

Light-induced degradation (LID) has been shown to significantly affect the performance of multicrystalline silicon (mc-Si) solar cells with aluminium oxide (AlOx) passivated rear side. Within this work, the impact of LID on the conversion efficiency of different silicon solar cell architectures with and without AlOx passivation is investigated. Under conditions representing realistic module operation, significant light-induced degradation of up to Δη = -2.9 %relin conversion efficiency has been observed for multicrystalline silicon (mc-Si)solar cells with AlOxpassivation. This degradation has been found to be higher than the degradation of, both,a mc-Si aluminium back surface field(Al-BSF) solar cell and, remarkably, a Czochralski-grown silicon (Cz-Si) solar cell with AlOx passivation. For a more detailed investigation of the interaction of mc-Si and AlOx passivation during degradation,a photoluminescence-based“effective defect”imaging has been performed on AlOx-passivated mc-Si lifetime samples. The local effective defect lifetimerelated to recombination due toLID-induced defects is found to vary strongly in the range of τeff,defect = 5 to 75 μs and, furthermore, areas with low effective lifetime could be identified as areas with relatively high dislocation density.