SCAPS-1D Modeling of Hydrogenated Lead-Free Cs₂AgBiBr₆ Double Perovskite Solar Cells with a Remarkable Efficiency of 26.3%

In this investigation, we employ a numerical simulation approach to model a hydrogenated lead-free ${\mathrm{C}\mathrm{s}}_2\mathrm{A}\mathrm{g}\mathrm{B}\mathrm{i}{\mathrm{B}\mathrm{r}}_6$ double perovskite solar cell with a p-i-n inverted structure, utilizing SCAPS-1D. Contrary to traditional lead-based perovskite solar cells, the ${\mathrm{C}\mathrm{s}}_2\mathrm{A}\mathrm{g}\mathrm{B}\mathrm{i}{\mathrm{B}\mathrm{r}}_6$ double perovskite exhibits reduced toxicity and enhanced stability, boasting a maximum power conversion efficiency of $\mathrm{6.37\%}$. Given its potential for improved environmental compatibility, achieving higher efficiency is imperative for its practical implementation in solar cells. This paper offers a comprehensive quantitative analysis of the hydrogenated lead-free ${\mathrm{C}\mathrm{s}}_2\mathrm{A}\mathrm{g}\mathrm{B}\mathrm{i}{\mathrm{B}\mathrm{r}}_6$ double perovskite solar cell, aiming to optimize its structural parameters. Our exploration involves an in-depth investigation of various electron transport layer materials to augment efficiency. Variables that affect the photovoltaic efficiency of the perovskite solar cell are closely examined, including the absorber layer’s thickness and doping concentration, the hole transport layer, and the absorber defect density. We also investigate the impact of the doping concentration of the electron transport layer and the energy level alignment between the absorber and the interface on the photovoltaic output of the cell. After careful consideration, zinc oxide is chosen to serve as the electron transport layer. This optimized configuration surpasses the original structure by over four times, resulting in an impressive power conversion efficiency of $\mathrm{26.3\%}$, an open-circuit voltage of $1.278 \mathrm{V}$, a fill factor of $\mathrm{88.21\%}$, and a short-circuit current density of $23.30 \mathrm{m}\mathrm{A}.{\mathrm{c}\mathrm{m}}^{-2}$. This study highlights the critical role that numerical simulations play in improving the chances of commercializing Cs₂AgBiBr₆ double perovskite solar cells through increased structural optimization and efficiency.