Effect of combined treatment of cesium fluoride as precursor and post-treatment on Cu(In,Ga)Se2 thin film solar cell

In this study, we investigate the combined effect of cesium fluoride (CsF) as a precursor and post-treatment on a Cu(In-x,Ga1-x)Se-2 (CIGS) thin film solar cell fabricated onto sodalime glass substrates. The combined treatment improves the open-circuit voltage, fill factor, and cell efficiency of the solar cell compared with its single counter treatment. Secondary ion mass spectroscopy measurements show a higher concentration of Cs diffusion in the surface regions in the combined treatment, which change the electronic properties of the buffer/CIGS interface by reducing interfacial recombination. Solar cells fabricated using CsF as a precursor indicate a deterioration in device performance owing to the formation of bulk defects, as confirmed from admittance spectroscopy. This study unveils device performance improvement by combining a heavy alkali metal as a precursor and post-treatment on CIGS thin film solar cells.

Automated summary

This study explores the combined effect of cesium fluoride as a precursor and post-treatment on CIGS thin film solar cells, revealing improved device performance in terms of open-circuit voltage, fill factor, and cell efficiency. While the combined treatment reduces interfacial recombination by increasing Cs diffusion, it does not prevent the formation of bulk defects that lead to deterioration in device performance.