Performance improvement and optimization of Cs₂TiI₂Br₄ perovskite solar cells with diverse charge transport materials via numerical analysis

As the next generation of photovoltaic devices , perovskite solar cells (PSCs) are garnering a lot of attention because of their superior photovoltaic characteristics and suitability for large-scale deposition procedures. However, the commercialization is impeded by the presence of harmful lead components. In this study, to discover the greatest feasible efficiency, lead-free Cs 2 TiI 2 Br 4 -based perovskite material has been simulated and optimized using SCAPS 1d. Sb 2 S 3 has been determined to be the most appropriate HTL among the five, utilizing the FTO/ZnSe/Cs 2 TiI 2 Br 4 /HTL/Au structure. Four separate structures are generated in the configuration of FTO/ETL/Cs 2 TiI 2 Br 4 /Sb 2 S 3 /Au using four different ETLs (CdZnS, PC 60 BM, SnS 2 , and ZnSe). We have observed and optimized the effects of absorber and ETL thickness, acceptor and absorber defect density , and HTL defect density . For the final optimized structures, the dominance of temperature, shunt and series resistances, and JV and QE characteristics curves are also noted. FTO/ZnSe/Cs 2 TiI 2 Br 4 /Sb 2 S 3 /Au exhibits the greatest performance among the other structures upon optimization, with a V OC of 1.265 V, a J SC of 24.44 mA/cm 2 , an FF of 89.77 %, and a PCE of 27.75 %. • Cs₂TiI₂Br₄ perovskite is used as absorber for numerical analysis of solar cell devices via SCAPS-1D. • Optimized Structure: The FTO/ETL/Cs 2 TiI 2 Br 4 /Sb 2 S 3 /Au structure has been investigated with four different ETLs to find best combination. • Material Tuning: Cs₂TiI₂Br₄ absorber, Sb 2 S 3 HTL, ETLs like CdZnS, PC 60 BM, SnS 2 , and ZnSe thickness, acceptor, donor and defect density. • Quantum Efficiency: Optimized structures showed higher EQE than initial structures, showcasing optimized light absorption.