Performance optimization of earth abundant CZTS Kesterite solar cell with efficient interface engineering and back surface field

In this work, we introduce a double CZTS-layered design with a high-performance Electron Transport Layer (ETL) as an effective way to increase the efficiency of Kesterite solar cells. Our modeling methodology comprehensively considers various loss mechanisms, such as radiative recombination, defect and trap densities within the bulk CZTS, and the ETL/CZTS interface. The predictive capabilities of our modeling are validated next to experimental data, showcasing a strong correlation. Exploring key factors influencing solar cell performance, including band alignment, interfacial traps, doping, and the thickness of different device layers, we aim to optimize the solar cell design. Addressing the challenges associated with the CdS/CZTS interface, we investigate alternative eco-friendly window materials like TiO₂, ZnO, and In₂S₃. Our findings highlight that TiO₂, with its superior optical and electrical properties, significantly enhances overall solar cell performance. The proposed design effectively mitigates the undesirable effects of recombination, particularly at the CdS/CZTS interface. Besides, the BSF layer improve the device in terms of efficiency by reducing the recombination losses. Comparative analysis reveals a noteworthy increase in efficiency, with our optimized design achieving an impressive 12.75%, surpassing the baseline device efficiency of 8.8%. The advantages of our suggested structure extend to enhanced absorption behavior and decreased recombination effects, marking a significant stride toward more efficient and sustainable Kesterite solar cells.