High-performance optimization and analysis of Cs₂AgBiBr₆-based lead-free double perovskite solar cells

Abstract

This work focuses on designing novel perovskite solar cells (PSCs) by working on the stability issues, the presence of lead in the PSC's structure, and its innately low efficiency. This work aims to overcome lead-based PSCs' shortcomings by optimizing various parameters of the double perovskite absorber layer and hole transport layer (HTL). The double perovskite ${\mathrm{Cs}}_{2}{\mathrm{AgBiBr}}_{6}$ material has been utilized as an absorber. The device performances are investigated with $\mathrm{Spiro\,OMeTAD\, (S.O.)}$, ${\mathrm{Cu}}_{2}\mathrm{O}$, ${\mathrm{MASnBr}}_{3}$, ${\mathrm{P}}_{3}\mathrm{HT}$, ${\mathrm{Ni}}_{1-x}\mathrm{O}$, and Cu-doped ${\mathrm{Ni}}_{1-x}\mathrm{O}$ as HTLs and Mg-doped $\mathrm{ZnO}$ ${(\mathrm{Zn}}_{x}{\mathrm{Mg}}_{1-x}\mathrm{O})$ as electron transport layer (ETL). Cu-doped ${\mathrm{Ni}}_{1-x}\mathrm{O}$ significantly boosts the performance of lead-free double perovskite-based solar cells. The device shows maximum power conversion efficiency (PCE) of 20.06%, Open-circuit voltage ($V_{\mathrm{oc}})$ of 1.68 V, Short-circuit current density ($J_{\mathrm{sc}}$) of 14.81 ${\mathrm{mA}/\mathrm{cm}}^{2},$ and Fill-factor (FF) of 80.54%. Also, the effect of changing series resistance, shunt resistance, and temperature on the optimized device has been investigated. The optimized device shows more immunity and stability against temperature variations. These results can be utilized for designing high-performance, eco-friendly perovskite solar cells in the future. This study suggests that ${\mathrm{Cs}}_{2}{\mathrm{AgBiBr}}_{6}$ and some other double perovskites can be utilized as an important absorber toward the stable and efficient lead-free and inorganic PSCs for future eco-friendly technologies.