Optimizing CuSbS₂ Heterojunction Solar Cell Efficiency Through Back Surface Field Layer

Copper-based ternary chalcogenides have garnered considerable attention as promising absorber materials for heterojunction thin-film solar cells (HJTFSCs) due to their favorable optoelectronic properties, including optimal band gap, high absorption coefficient, low cost, non-toxicity, sustainability, and environmental compatibility. Recent advancements in both experimental synthesis and numerical modeling have aimed to enhance the performance of these materials in photovoltaic applications. In this study, we investigate the performance of a p-type CuSbS₂ (CAS)-based HJTFSC structure incorporating a back surface field (BSF), using the one-dimensional Solar Cell Capacitance Simulator (SCAPS-1D). The proposed device architecture comprises ZnO:Al/i-ZnO/n-CdS/p-CAS/p⁺- CAS/Mo layers. SCAPS-1D enables comprehensive analysis of the electronic and optical behavior of each layer, accounting for parameters such as thickness, carrier concentration, band gap, electron affinity, and other relevant material properties. Simulations were conducted under standard test conditions (AM 1.5 solar spectrum, 100 mW/cm² illumination, 300 K), with a front internal transmission coefficient of unity and an applied reverse voltage ranging from 0 to -1 V. The results provide detailed insight into the key performance metrics of the p⁺-p-n heterostructure, including short-circuit current density (Jsc), open-circuit voltage (Voc), fill factor (FF), power conversion efficiency (η), and quantum efficiency (QE). This work contributes to the optimization of copper-based chalcogenide solar cells and underscores the potential of CAS-based architectures for high-efficiency, sustainable photovoltaics.