XPS profiling study of Al2O3 passivation layers for high efficiency n-PERT and PERC solar cells

Even if silicon solar cells are leader on the worldwide market, research keeps to investigate how to go on increasing the efficiencies. Among the different technologies developed, PERC and n-PERT cells are at present the most promising ones. The fine optimization of those more and more complex structures not only rely on the stack constitution but also on the interfaces properties and quality in-between each layer, and especially the interfaces involving the passivation layers. To this end, XPS profiling is employed in this study to accurately determine the precise chemical composition and local atomic network at those critical interfaces, i.e. between c-Si and the passivation layers, focusing particularly on Al
₂
O
₃
passivation layer one.