Effects of electron-phonon coupling on absorption spectrum: K edge of hexagonal boron nitride

Autor(en)

Ferenc Karsai, Moritz Humer, Flage-Larsen Espen, Blaha Peter, Georg Kresse

Abstrakt

A detailed analysis of the theoretical x-ray absorption near-edge structures (XANES) for the boron and nitrogen K edge in hexagonal boron nitride (h-BN) employing density-functional theory calculations is presented. The supercell core-hole method and the Bethe-Salpeter equation are used for the description of electron-hole interactions. The calculations are carried out with two different codes, the vasp and the wien2k codes, employing the projector augmented-wave and the full-potential linear augmented-plane-wave methods, respectively. We find close agreement between spectra obtained from the two codes and between calculations using the supercell core-hole method and the Bethe-Salpeter approach. All our calculations, as well as previous calculations using the ground-state structure, yield a single 2pσ∗ peak in the boron K-edge spectrum and hence fail to describe the experimental double-peak structure. We find that the inclusion of electron-phonon interactions is crucial to obtain the experimentally observed double-peak structure. We include these effects fully parameter free and ab initio using a one-shot sampling method and obtain excellent agreement with experiment.

Organisation(en)

Computergestützte Materialphysik

Externe Organisation(en)

SINTEF The Foundation for Scientific and Industrial Research at the Norwegian Institute of Technology (NTH), Technische Universität Wien, Universität Wien

Journal

Physical Review B

Band

98

Anzahl der Seiten

10

ISSN

2469-9950

DOI

https://doi.org/10.1103/PhysRevB.98.235205

Publikationsdatum

12-2018

Peer-reviewed

Ja

ÖFOS 2012

103018 Materialphysik

Schlagwörter

ASJC Scopus Sachgebiete

Electronic, Optical and Magnetic Materials, Condensed Matter Physics

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/595a5614-e6cb-4290-81b5-366ebe1fce60