Optical properties of In₂O₃ from experiment and first-principles theory: influence of lattice screening

Abstract

The framework of many-body perturbation theory led to deep insight into electronic structure and optical properties of diverse systems and, in particular, many semiconductors. It relies on an accurate approximation of the screened Coulomb electron-electron interaction W, that in current implementations is usually achieved by describing electronic interband transitions. However, our results for several oxide semiconductors indicate that for polar materials it is necessary to also account for lattice contributions to dielectric screening. To clarify this question in this work, we combine highly accurate experimentation and cutting-edge theoretical spectroscopy to elucidate the interplay of quasiparticle and excitonic effects for cubic bixbyite In 2 O 3 across an unprecedentedly large photon energy range. We then show that the agreement between experiment and theory is excellent and, thus, validate that the physics of quasiparticle and excitonic effects is described accurately by these firstprinciples techniques, except for the immediate vicinity of the absorption onset. Finally, our combination of experimental and computational data clearly establishes the need for including a lattice contribution to dielectric screening in the screened electron-electron interaction, in order to improve the description of excitonic effects near the absorption edge.

Database‐Driven Materials Selection for Semiconductor Heterojunction Design

“…Since in both the GGA and HSE06 calculations the band gaps are corrected to the same experimental values, the observed shifts of E BP are due to changes in band dispersion. More specifically, the HSE06 functional better reproduces the energy dependence of QP corrections, which leads to larger shifts the higher or lower states are in energy, compared to states near the VBM and CBM . Overall this shows that both spin‐orbit coupling and QP energy corrections to the band structure are ruled out as sources of disagreement between the experimental and computed values.…”

The GW Compendium: A Practical Guide to Theoretical Photoemission Spectroscopy

“…Ab-initio GW /BSE calculations focused on semiconductors like Si, GaAs, and Li 2 O where GW /BSE produces optical absorption spectra and exciton binding energies in close agreement with experiment (Onida et al, 1995b; Albrecht et al, 1997, 1998a,b; Benedict et al, 1998a,b; Rohlfing and Louie, 1998, 2000; Benedict and Shirley, 1999). Similar to the proliferation of GW since its early successes, GW /BSE has been applied extensively to solids (Schleife et al, 2011, 2018; Rinke et al, 2012; Erhart et al, 2014), molecules (Körbel et al, 2014; Bruneval et al, 2015; Jacquemin et al, 2015), surfaces (Palummo et al, 2004), and two-dimensional materials (Komsa and Krasheninnikov, 2012; Ramasubramaniam, 2012; Hüser et al, 2013a; Qiu et al, 2013, 2016; Shi et al, 2013; Ugeda et al, 2014; Dvorak and Wu, 2015). As with Dyson's equation, equations with the Bethe-Salpeter form appear in different contexts in many-body theory.…”

Low-cost alternatives to the Bethe-Salpeter equation: Towards simple hybrid functionals for excitonic effects in solids

“…Furthermore, the ε(0) or γ in the m-BSE and SXX can also be treated as empirically adjustable parameters. Such flexibility could be helpful when the RPA dielectric function alone is not sufficiently accurate for excitonic effects, for instance, due to the presence of lattice screening effects [67]. We use the definition of the screening parameter in Eq.…”