Improved quasiparticle self-consistent electronic band structure and excitons in β-LiGaO2

TY - JOUR

T1 - Improved quasiparticle self-consistent electronic band structure and excitons in β-LiGaO2

AU - Dadkhah, Niloufar

AU - Lambrecht, Walter R.L.

AU - Pashov, Dimitar

AU - Van Schilfgaarde, Mark

N1 - Funding Information: The work at CWRU was supported by the U.S. Department of Energy Basic Energy Sciences (DOE-BES) under Grant No. DE-SC0008933. Calculations made use of the High Performance Computing Resource in the Core Facility for Advanced Research Computing at Case Western Reserve University and the Ohio Supercomputer Center. D.P. and M.v.S. were supported by the DOE-BES, Division of Chemical Sciences, under Contract No. DE-AC36-08GO28308. Publisher Copyright: © 2023 American Physical Society.

PY - 2023/4/15

Y1 - 2023/4/15

N2 - The band structure of β-LiGaO2 is calculated using the quasiparticle self-consistent QSGŴ method where the screened Coulomb interaction Ŵ is evaluated including electron-hole interaction ladder diagrams and G is the one-electron Green's function. Improved convergence compared to previous calculations leads to a significantly larger band gap of about 7.0 eV. However, exciton binding energies are found to be large and lead to an exciton gap of about 6.0 eV if also a zero-point-motion correction of about -0.4 eV is included. These results are in excellent agreement with recent experimental results on the onset of absorption. Besides the excitons observed thus far, the calculations indicate the existence of a Rydberg-like series of exciton excited states, which is however modified from the classical Wannier exciton model by the anisotropies of the material and the more complex mixing of Bloch states in the excitons resulting from the Bethe-Salpeter equation. The exciton fine structure and the exciton wave functions are visualized and analyzed in various ways.

AB - The band structure of β-LiGaO2 is calculated using the quasiparticle self-consistent QSGŴ method where the screened Coulomb interaction Ŵ is evaluated including electron-hole interaction ladder diagrams and G is the one-electron Green's function. Improved convergence compared to previous calculations leads to a significantly larger band gap of about 7.0 eV. However, exciton binding energies are found to be large and lead to an exciton gap of about 6.0 eV if also a zero-point-motion correction of about -0.4 eV is included. These results are in excellent agreement with recent experimental results on the onset of absorption. Besides the excitons observed thus far, the calculations indicate the existence of a Rydberg-like series of exciton excited states, which is however modified from the classical Wannier exciton model by the anisotropies of the material and the more complex mixing of Bloch states in the excitons resulting from the Bethe-Salpeter equation. The exciton fine structure and the exciton wave functions are visualized and analyzed in various ways.

UR - http://www.scopus.com/inward/record.url?scp=85158842108&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.107.165201

DO - 10.1103/PhysRevB.107.165201

M3 - Article

AN - SCOPUS:85158842108

SN - 2469-9950

VL - 107

JO - Physical Review B

JF - Physical Review B

IS - 16

M1 - 165201

ER -