The present study analyzes a high-efficiency CIGS-based heterojunction solar cell with structure Al/i-ZnO/Buffer/CIGS/Ni, designed and simulated using SCAPS-1D. The impact of several buffer layers (CdS, SnS 2 , and In 2 S 3 ) on device performance was examined. Incorporating a back surface field (BSF) layer enhanced carrier collection and decreased recombination losses. Iterative simulations were conducted to optimize absorber and buffer thicknesses along with defect characteristics. The optimized device achieves around 21% efficiency with short circuit current (J S ) = 43.6 mA/cm 2 , open circuit voltage (V OC ) = 0.6015 V, and fill factor (FF) = 82.36%, without BSF. With the inclusion of BSF, the efficiency increased to 22.6% with V OC enhanced to 0.627 V and FF to 82.90%, while maintaining the same J SC . The best performance was obtained with a 3 μm absorber layer and an approximately 20 nm buffer layer. Furthermore, reducing interface recombination significantly enhanced the output. These findings demonstrate the potential of this cadmium-free structure as a cost-effective and stable choice for next-generation photovoltaic applications.
Akter et al. (Fri,) studied this question.