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Optical Absorption and Photoluminescence of Single-Layer Boron Nitride from a First-Principles Cumulant Approach.
- Source :
-
Nano letters [Nano Lett] 2024 May 22; Vol. 24 (20), pp. 6017-6022. Date of Electronic Publication: 2024 May 09. - Publication Year :
- 2024
-
Abstract
- The photoluminescence spectrum of a single-layer boron nitride remains elusive, marked by enigmatic satellites that hint at significant but unidentified exciton-phonon coupling. Here, by employing a first-principles approach based on the many-body cumulant expansion of the charge response, we calculate the optical absorption and photoluminescence of a single-layer boron nitride. We identify the specific exciton-phonon scattering channels and unravel their impact on the optical absorption and photoluminescence spectra, thereby providing an interpretation of the experimental features. Finally, we show that, even in a strongly polar material such as h-BN monolayer, the electron-hole interaction responsible for the excitonic effect results in the cancellation of the Frölich interaction at small phonon momenta. This effect is captured only if the invariance of the exciton-phonon matrix elements under unitary transformations in the Bloch function manifold is preserved in the calculation.
Details
- Language :
- English
- ISSN :
- 1530-6992
- Volume :
- 24
- Issue :
- 20
- Database :
- MEDLINE
- Journal :
- Nano letters
- Publication Type :
- Academic Journal
- Accession number :
- 38723148
- Full Text :
- https://doi.org/10.1021/acs.nanolett.4c00669