Structural distortions control scaling of exciton binding energies in two-dimensional Ag/Bi double perovskites.

ABSTRACT: Three-dimensional metal halide double perovskites such as Cs₂AgBiBr₆ exhibit pronounced excitonic effects due to their anisotropic electronic structure and chemical localization effects. Their two-dimensional derivatives, formed by inserting organic spacer molecules between perovskite layers, were expected to follow well-established trends seen in Pb-based 2D perovskites, namely, increasing exciton binding energies with decreasing layer thickness due to enhanced quantum and dielectric confinement. However, recent experimental and computational studies have revealed anomalous behavior in Ag/Bi-based 2D perovskites, where this trend is reversed. Using ab initio many-body perturbation theory within the GW and Bethe-Salpeter Equation frameworks, we resolve t

SUBMITTER: Lechifflart P 

PROVIDER: S-EPMC12495387 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature