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Impact of strain on the optical fingerprint of monolayer transition-metal dichalcogenides
Impact of strain on the optical fingerprint of monolayer transition-metal dichalcogenides
- Source :
- Physical Review B
-
Abstract
- Strain presents a straightforward tool to tune electronic properties of atomically thin nanomaterials that are highly sensitive to lattice deformations. While the influence of strain on the electronic band structure has been intensively studied, there are only a few works on its impact on optical properties of monolayer transition-metal dichalcogenides (TMDs). Combining microscopic theory based on Wannier and Bloch equations with nearest-neighbor tight-binding approximation, we present an analytical view on how uni- and biaxial strain influences the optical fingerprint of TMDs, including their excitonic binding energy, oscillator strength, optical selection rules, and the radiative broadening of excitonic resonances. We show that the impact of strain can be reduced to changes in the lattice structure (geometric effect) and in the orbital functions (overlap effect). In particular, we demonstrate that the valley-selective optical selection rule is softened in the case of uniaxial strain due to the introduced asymmetry in the lattice structure. Furthermore, we reveal a considerable increase of the radiative dephasing due to strain-induced changes in the optical matrix element and the excitonic wave functions.
- Subjects :
- Materials science
Condensed matter physics
Condensed Matter - Mesoscale and Nanoscale Physics
Oscillator strength
Dephasing
FOS: Physical sciences
02 engineering and technology
021001 nanoscience & nanotechnology
01 natural sciences
Condensed Matter::Materials Science
Bloch equations
Lattice (order)
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
0103 physical sciences
Monolayer
Radiative transfer
Microscopic theory
010306 general physics
0210 nano-technology
Electronic band structure
Subjects
Details
- Language :
- English
- ISSN :
- 24699969 and 24699950
- Volume :
- 96
- Issue :
- 4
- Database :
- OpenAIRE
- Journal :
- Physical Review B
- Accession number :
- edsair.doi.dedup.....5f952e31be200150851c25efed2433fc
- Full Text :
- https://doi.org/10.1103/physrevb.96.045425