Inline inspection of CIGS solar cells by means of Raman spectroscopy and photoluminescence imaging

Copper Indium Gallium Selenide (CIGS) thin-film solar cells are a promising technology, but inline quality inspection systems are required for efficient high-volume production. Tests with two candidate methods: Raman spectroscopy and photo-luminescence imaging, are reported in this paper. The methods were used to estimate material compositions of CIGS samples that were varied in absorber thickness and the composition of the CIGS absorber layer. Our results indicate that both methods can be valuable for contact-free inline inspection during the manufacture of CIGS solar cells, both individually and in combination.