Role of metal impurities in multicrystalline silicon solar cell degradation

Controlling light- and elevated temperature-induced degradation (LeTID) is one of the great challenges in silicon photovoltaics industry. Here, we performed systematic high-resolution elemental mapping and spectroscopic electrical measurements in multi-crystalline silicon wafers that underwent standard solar cell processing during LeTID. The prominent correlations between the metal precipitate formation/dissociation steps and the appearance of band-like or localized electronic states during LeTID evolution were observed. Of note, the re-precipitation of iron was found to co-localize with copper atom agglomerations. Finally, we discuss the potential mechanisms that enhance metal redistributions in mc-Si during LeTID in the context of the existing literature.

Automated summary

The study found significant correlations between the formation/dissociation of metal precipitates and the appearance of electronic states during LeTID evolution, as well as the co-localization of iron re-precipitation with copper atom agglomerations. This sheds light on potential mechanisms that enhance metal redistributions in mc-Si during LeTID.