Auteur(s): Vuong P., Cassabois G.
, Valvin P., Liu Song, Edgar Jim, Gil B.
(Article) Publié:
Physical Review B, vol. 95 p.201202(R) (2017)
Texte intégral en Openaccess : 
Ref HAL: hal-01528598_v1
DOI: 10.1103/PhysRevB.95.201202
WoS: 000402051300001
Exporter : BibTex | endNote
13 Citations
Résumé:
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 line shape 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 hexagonal boron nitride. Thus the theoretical predictions of Toyozawa [Prog. 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.