Enhanced solar cell efficiency: copper zinc tin sulfide absorber thickness and defect density analysis

Copper zinc tin sulfide solar cell (CZTS), Cu 2 ZnSnS 4 -based solar cells have shown promising conversion efficiency because of their ease of variation in configurations. In this work, the architecture of a ZnO–Al/i–ZnO/n–CdS/CZTS/Mo solar cell was optimized by using Silvaco Atlas simulation software. In this simulation study, the thickness and defect density of the CZTS layer has been varied to achieve the highest efficiency of 26.58%, with Isc = 36.64 A and Voc = 0.909 V at a defect density of 1.8 × 10 12 cm −3 . Increase in the layer thickness of CZTS improves the photon absorption and cell efficiency. This study has evidenced the impact of defect density on the absorber layer, including photo-generation rate, recombination rate, and solar cell efficiency. By optimizing the device parameters, it has achieved a fill factor of 79.74% under AM 1.5 illumination, demonstrating the potential for low-cost, highly efficient CZTS solar cells.