Accurate many-body calculation of electronic and optical band gap of bulk hexagonal boron nitride
| Autor: | František Karlický, Miroslav Kolos |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
GW approximation
Materials science Absorption spectroscopy Band gap business.industry Stacking General Physics and Astronomy 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Molecular physics Spectral line 0104 chemical sciences Brillouin zone Physical and Theoretical Chemistry Photonics 0210 nano-technology Electronic band structure business |
| Zdroj: | Physical chemistry chemical physics : PCCP. 21(7) |
| ISSN: | 1463-9084 |
| Popis: | Many-body perturbational GW approximation in conjunction with the Bethe-Salpeter equation (BSE) has been employed to calculate accurate electronic and optical band gaps of bulk hexagonal boron nitride (h-BN) in the two most important stacking configurations, AA' and AB. The carefully converged results revealed h-BN as an indirect material (indirect gap ≈ 6.1 eV) with a huge excitonic effect (≈0.8 eV) in perfect agreement with recent experiments [Nat. Photonics, 2016, 10, 262; Appl. Phys. Lett., 2016, 109, 122101]. The K-H region of the first Brillouin zone has been shown as the most important for lowest optical excitations in h-BN. Surprisingly, simple scissor corrected DFT has described h-BN band structure at the GW level and subsequent time-dependent DFT with a suitable exchange correlation kernel has provided absorption spectra similar to the full GW+BSE spectra. |
| Databáze: | OpenAIRE |
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