Comparative Analysis of Earth–Abundant Kesterite Solar Cells: Performance Evaluation of CZTS/CZTSe/CZTSSe Absorber Layers Using SCAPS–1D

This study presents a comparative performance analysis of kesterite-based solar cells, utilizing absorber layers of CZTS, CZTSe, and CZTSSe. Kesterite materials, renowned for their earth abundance, non-toxicity, and cost-effectiveness, hold significant promise as p-type absorbers in photovoltaic applications. Their direct bandgap, adjustable between 1.0 eV and 1.5 eV by tailoring the selenium-to-sulfur ratio, makes them suitable for high-efficiency solar cells. The simulated device structure comprises ZnO:Al as the window layer, ZnSe as the buffer layer, CZTS/CZTSe/CZTSSe as the absorber layers, and graphene oxide (GO) as the hole transport layer (HTL). Through SCAPS-1D simulations, key parameters such as open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), and power conversion efficiency (PCE) are analyzed. The study further investigates the effects of absorber thickness, doping concentration of the absorber, electron transport layer (ETL), and HTL, as well as series and shunt resistances. Among the studied configurations, the CZTSSe-based solar cell demonstrates superior performance with a Voc of 0.9367 V, Jsc of 37.44 mA/cm², FF of 82.68%, and a PCE of 30.01%. This research highlights the pivotal role of material composition and device optimization in achieving high-efficiency solar cells. The findings provide valuable insights for the development of advanced kesterite-based photovoltaics, identifying CZTSSe as the most promising absorber material for next-generation solar cells due to its superior performance metrics and tunable properties.