Advanced Computational Study on 144 Combinations of ETL & HTL Layers for High-Performance Cs₂TeI₆ Solar Cells

In this study, the performance optimization of Cs₂TeI₆-based solar cells by examining 144 unique combinations of 12-hole transport layers (HTLs) and 12-electron transport layers (ETLs), as well as the effects of three back contacts are explored. Additionally, the impact of temperature on the device performance is thoroughly investigated. The extensive optimization process involves the use of SCAPS, which allows for fine-tuning of key parameters such as the acceptor density, donor density, trap density, thicknesses of the absorber, ETL, and HTL, also series and shunt resistances and density functional theory calculations implemented to conduct investigation of the optical properties of the inorganic perovskite derivative Cs₂TeI₆. By optimizing these parameters, Cs₂TeI₆ as the absorber, WS₂ as the ETL, and copper barium tin sulfide as the HTL are identified. This optimized configuration demonstrates remarkable performance, achieving a power conversion efficiency of 26.57%, a fill factor of 91.10%, a short-circuit current density (J_SC) of 19.69 mA cm⁻², and open-circuit voltage (V_oc) of 1.48 V. This study of combination of ETL, HTL and back contact with Cs₂TeI₆ distinguishes this work, establishing new benchmarks for next-generation photovoltaic research. This comparative advantage in material selection, coupled with multi-parameter optimization, establishes new pathways for high-efficiency perovskite solar cells.