| Title | Influence of high-energy local orbitals and electron-phonon interactions on the band gaps and optical absorption spectra of hexagonal boron nitride |
| Authors | Shen, Tong Zhang, Xiao-Wei Shang, Honghui Zhang, Min-Ye Wang, Xinqiang Wang, En-Ge Jiang, Hong Li, Xin-Zheng |
| Affiliation | Peking Univ, State Key Lab Artificial Microstruct & Mesoscop P, Frontier Sci Ctr Nanooptoelect, Beijing 100871, Peoples R China Peking Univ, Sch Phys, Beijing 100871, Peoples R China Peking Univ, Int Ctr Quantum Mat, Beijing 100871, Peoples R China Chinese Acad Sci, Inst Comp Technol, State Key Lab Comp Architecture, Beijing 100871, Peoples R China Peking Univ, Coll Chem & Mol Engn, Beijing Natl Lab Mol Sci, Beijing 100871, Peoples R China Peking Univ, Collaborat Innovat Ctr Quantum Matter, Beijing 100871, Peoples R China Chinese Acad Sci, Inst Phys, Songshan Lake Lab, Ceram Div, Dongguan 523808, Guangdong, Peoples R China Liaoning Univ, Sch Phys, Shenyang 110036, Peoples R China |
| Issue Date | 13-Jul-2020 |
| Publisher | PHYSICAL REVIEW B |
| Abstract | We report ab initio band diagram and optical absorption spectra of hexagonal boron nitride (h-BN), focusing on unravelling how the completeness of the basis set for GW calculations and electron-phonon interactions (EPIs) impact on them. The completeness of the basis set, an issue which was seldom discussed in previous optical spectra calculations of h-BN, is found crucial in providing converged quasiparticle band gaps. In the comparison among three different codes, we demonstrate that by including high-energy local orbitals in the all-electron linearized augmented plane waves based GW calculations, the quasiparticle direct and fundamental indirect band gaps are widened by similar to 0.2 eV, giving values of 6.81 eV and 6.25 eV, respectively at the GW(0) level. EPIs, on the other hand, reduce them to 6.62 eV and 6.03 eV respectively at 0 K, and 6.60 eV and 5.98 eV respectively at 300 K. With clamped crystal structure, the first peak of the absorption spectrum is at 6.07 eV, originating from the direct exciton contributed by electron transitions around K in the Brillouin zone. After including the EPIs-renormalized quasiparticles in the Bethe-Salpeter equation, the exciton-phonon coupling shifts the first peak to 5.83 eV at 300 K, lower than the experimental value of similar to 6.00 eV. This accuracy is acceptable to an ab initio description of excited states with no fitting parameter. |
| URI | http://hdl.handle.net/20.500.11897/617267 |
| ISSN | 2469-9950 |
| DOI | 10.1103/PhysRevB.102.045117 |
| Indexed | SCI(E) |
| Appears in Collections: | 其他实验室 人工微结构和介观物理国家重点实验室 量子材料科学中心 å å¦ä¸ å å å·¥ç¨ å¦é ¢ |
