SciPost Physics

SciPost Phys. 12, 145 (2022) · published 4 May 2022

• doi: 10.21468/SciPostPhys.12.5.145
• pdf
• BiBTeX
• RIS
• Submissions/Reports
• 

Abstract

Hexagonal boron nitride is an indirect band gap material with a strong luminescence in the ultraviolet. This luminescence originates from bound excitons recombination assisted by different phonon modes. The coupling between excitons and phonons is so strong that the resulting light emission is as efficient as the one of direct band gap materials. In this manuscript we investigate how uniaxial strain modifies the electronic and optical properties of this material, and in particular how it affects the exciton-phonon coupling. Using a formulation of this coupling based on finite-difference displacements, recently developed by some of us, we investigate how phonon-assisted transitions change under strain. Our results open the way to the study of phonon-assisted luminescence in strained materials from first principles. Our findings are important both for experiments that directly probe \hbn under strain or for those in which it is used as substrate for other 2D material with a lattice mismatch.

• Lechifflart et al., First-principles study of luminescence in hexagonal boron nitride single layer: Exciton-phonon coupling and the role of substrate
  Phys. Rev. Materials 7, 024006 (2023) [Crossref]
• Attaccalite et al., Interlayer and Intralayer Excitons in AlN/WS2 Heterostructure
  Materials 15, 8318 (2022) [Crossref]
• Zanfrognini et al., Effect of uniaxial strain on the excitonic properties of monolayer C3N : A symmetry-based analysis
  Phys. Rev. B 107, 045430 (2023) [Crossref]
• Silvetti et al., Pressure dependence of electronic, vibrational and optical properties of wurtzite-boron nitride
  Phys. Rev. Materials 7, 055201 (2023) [Crossref]