First-principles study of excitons in the optical spectra of silver chloride

Arnaud Lorin (1, 2) , Matteo Gatti (1, 3, 2) , Lucia Reining (1, 2) , Francesco Sottile (1, 2)

1 LSI - Laboratoire des Solides Irradiés - Irradiated Solids Laboratory
2 ETSF - European Theoretical Spectroscopy Facility
3 SSOLEIL - Synchrotron SOLEIL

Silver chloride is a material that has been investigated and used for many decades. Of particular interest are its optical properties, but only few fundamental theoretical studies exist. We present first-principles results for the optical properties of AgCl, obtained using time-dependent density functional theory and many-body perturbation theory. We show that optical properties exhibit strong excitonic effects, which are correctly captured only by solving the Bethe-Salpeter equation starting from quasiparticle self-consistent GW results. Numerical simulations are made feasible by using a model screening for the electron-hole interaction in a way that avoids the calculation of the static dielectric constant. A thorough analysis permits us to discuss localization in bright and dark excitons of silver chloride.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Arnaud Lorin, Matteo Gatti, Lucia Reining, Francesco Sottile. First-principles study of excitons in the optical spectra of silver chloride. Physical Review B, 2021, 104, pp.235149. ⟨10.1103/PhysRevB.104.235149⟩. ⟨hal-03215065v3⟩