Nature of exciton transitions in hexagonal boron nitride

Journal Article · Mon Mar 21 00:00:00 EDT 2016 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4944696· OSTI ID:22591466

Li, J.; Cao, X. K.; Lin, J. Y.; Hoffman, T. B.; Edgar, J. H. ^[1]

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1. Department of Chemical Engineering, Kansas State University, Manhattan, Kansas 66506 (United States)

In contrast to other III-nitride semiconductors GaN and AlN, the intrinsic (or free) exciton transition in hexagonal boron nitride (h-BN) consists of rather complex fine spectral features (resolved into six sharp emission peaks) and the origin of which is still unclear. Here, the free exciton transition (FX) in h-BN bulk crystals synthesized by a solution method at atmospheric pressure has been probed by deep UV time-resolved photoluminescence (PL) spectroscopy. Based on the separations between the energy peak positions of the FX emission lines, the identical PL decay kinetics among different FX emission lines, and the known phonon modes in h-BN, we suggest that there is only one principal emission line corresponding to the direct intrinsic FX transition in h-BN, whereas all other fine features are a result of phonon-assisted transitions. The identified phonon modes are all associated with the center of the Brillouin zone. Our results offer a simple picture for the understanding of the fundamental exciton transitions in h-BN.

• OSTI ID: 22591466
• Journal Information: Applied Physics Letters, Vol. 108, Issue 12; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALUMINIUM NITRIDES
ATMOSPHERIC PRESSURE
BORON NITRIDES
BRILLOUIN ZONES
CRYSTALS
GALLIUM NITRIDES
ORIGIN
PEAKS
PHONONS
PHOTOLUMINESCENCE
PROBES
SEMICONDUCTOR MATERIALS
SPECTROSCOPY
TIME RESOLUTION