DOI: 10.1103/PhysRevB.93.035207
WoS: 000369221000004
43 Citations
Résumé:

We report photoluminescence experiments bringing the evidence for intervalley scattering in bulk hexagonal boron nitride. From a quantitative analysis of the defect-related emission band, we demonstrate that transverse optical phonons at the K point of the Brillouin zone assist inter-K valley scattering, which becomes observable because stacking faults in bulk hexagonal boron nitride provide a density of final electronic states. Time-resolved experiments highlight the different recombination dynamics of the phonon replicas implying either virtual excitonic states or real electronic states in the structural defects.

Commentaires: Editors' suggestion: The authors have conducted an experimental study of hexagonal boron nitride using steady-state and time-resolved photoluminescence. The assignment of previously observed lines of unknown origin is made convincingly to indirect excitons assisted by acoustic and optical phonons and to defect-assisted transitions. This is further evidence for h-BN being an indirect band-gap semiconductor.