Degradation of Surface Passivation on Crystalline Silicon and Its Impact on Light-Induced Degradation Experiments

A decrease of surface passivation quality is observed in FZ, Cz, and mc-Si lifetime samples during light-induced degradation (LID) treatments. It is shown that this degradation occurs not only in samples with single SiN
_x
:H layers but also when using layer stacks consisting of SiO
_x
/SiN
_x
:H or AlO
_x
:H/SiN
_x
:H. Time-resolved calculation of the surface saturation current density J0s is shown to be a reliable method to separate changes in the bulk and at the surface of samples during LID treatments. The impact of the observed changes in passivation quality on the outcome and interpretation of LID experiments aiming at changes in the bulk of Cz or mc-Si is investigated and discussed.