High-throughput screening to modulate electronic and optical properties of alloyed Cs₂AgBiCl₆ for enhanced solar cell efficiency

The lead-free double perovskite material (viz. Cs$_2$AgBiCl$_6$) has emerged as an efficient and environmentally friendly alternative to lead halide perovskites. To make Cs$_2$AgBiCl$_6$ optically active in the visible region of solar spectrum, band gap engineering approach been undertaken. Using a host, optical properties have modulated by alloying with M(I), M(II), M(III) cations at Ag-/Bi-sites. Here, we employed density functional theory (DFT) suitable exchange-correlation functionals light spin-orbit coupling (SOC) determine stability, different compositions, that are obtained on Ag-Cl Bi-Cl sublattices mixing. On analyzing 64 combinations within Cs$_2$AgBiCl$_6$, identified 19 promising configurations having sensitive cell applications. most Ge(II) Sn(II) substitutions spectroscopic limited maximum efficiency (SLME) 32.08% 30.91%, respectively, which apt for absorber.