Fabrication and characterization of Cu (In, Ga) Se2 thin films by electrodeposition: optimization of the thermal treatment with selenium and mechanical disturbance technique

The evaporation technique fabricates solar cells using the Cu(In, Ga)Se2 (CIGS) absorber. This technique has strong limitations in preparing this absorber in a large area, necessitating the electrodeposition technique. However, the morphology and crystallinity of this absorber need to be sufficiently adequate to guarantee proper collection of charge carriers since a cauliflower-type growth is favored. This underscores the need for modifications during the synthesis, thermal treatments, and post-synthesis to improve the morphology and crystallinity, a complex and significant aspect of our research. This work discusses the structural, atomic composition, morphological, and optical results obtained for samples of CIGS films synthesized by the electrodeposition technique. We proudly report that we achieved the best atomic composition, close to the ideal and an adequate morphology, by selenizing the samples with 30 mg and a temperature of 570°C. This success was further enhanced by subjecting these films to constant periodic movement during their synthesis, leading to significant improvements in the crystallinity, a testament to the success of our research.