Exploring Lead Free Mixed Halide Double Perovskites Solar Cell

The significant surge in energy use and increased environmental concerns have sparked worldwide interest in studying and implementing solar cell technology. Perovskite solar cells (PSCs) have attracted considerable attention as an emerging third-generation solar cell technology. This paper presents an in-depth analysis of lead-free mixed-halide double perovskites in the context of their potential uses in solar cell technology. Through previous studies of various mixed halide double perovskite materials as potential absorber layer materials, it has been observed that $\mathrm{Cs}_{2} \mathrm{TiI}_{6-\mathrm{x}} \mathrm{Br}_{\mathrm{x}}$ possesses promising characteristics. This study performed simulations using SCAPS-1D software to explore all possible combinations for $x=0$ to 6. The materials for the Hole Transport Layer (HTL), Electron Transport Layer (ETL), and the absorber layer, along with their optimal thicknesses, are selected to yield the most promising results in terms of open-circuit voltage ($\mathbf{V}_{o c}$), short-circuit current density ($\mathbf{J}_{s c}$), fill factor (FF), and power conversion efficiency. A novel tolerance factor is used to assess the structural stability of perovskites. FTO/ $\mathrm{Cu}_{2} \mathrm{O} / \mathrm{Cs}_{2} \mathrm{TiI}_{5} \mathrm{Br}_{1} / \mathrm{WS}_{2}$ emerges as the best combination in terms of efficiency with 19.03% but $\mathrm{FTO} / \mathrm{Cu}_{2} \mathrm{O} / \mathrm{Cs}_{2} \mathrm{TiI}_{2} \mathrm{Br}_{4} / \mathrm{WS}_{2}$ shows good stability with 13.31% efficiency.