Exciton-phonon interaction in the strong coupling regime in hexagonal boron nitride

Abstract

The temperature-dependent optical response of excitons in semiconductors is controlled by the exciton-phonon interaction. When the exciton-lattice coupling is weak, the excitonic line has a Lorentzian profile resulting from motional narrowing, with a width increasing linearly with the lattice temperature $T$. In contrast, when the exciton-lattice coupling is strong, the lineshape is Gaussian with a width increasing sublinearly with the lattice temperature, proportional to $\sqrt{T}$. While the former case is commonly reported in the literature, here the latter is reported for the first time, for hexagonal boron nitride. Thus the theoretical predictions of Toyozawa [Progr. Theor. Phys. 20, 53 (1958)] are supported by demonstrating that the exciton-phonon interaction is in the strong coupling regime in this Van der Waals crystal.

arXiv commentsubmitted

References in corpus (4)

• Hexagonal boron nitride is an indirect bandgap semiconductor
• Huge excitonic effects in layered hexagonal boron nitride
• Unconventional motional narrowing in the optical spectrum of a semiconductor quantum dot
• Linewidths in excitonic absorption spectra of cuprous oxide

Cited by in corpus (8)

• Exciton-Phonon Interaction and Relaxation Times from First Principles
• Exciton-phonon coupling in the UV absorption and emission spectra of bulk hexagonal boron nitride
• Deep-ultraviolet electroluminescence and photocurrent generation in graphene/hBN/graphene heterostructures
• Phonon wind and drag of excitons in monolayer semiconductors
• Rotationally Aligned Hexagonal Boron Nitride on Sapphire by High-Temperature Molecular Beam Epitaxy
• Complexes of dipolar excitons in layered quasi-two-dimensional nanostructures
• The influence of high-energy local orbitals and electron-phonon interactions on the band gaps and optical spectra of hexagonal boron nitride
• Excitons under strain: light absorption and emission in strained hexagonal boron nitride