Hexagonal boron nitride as a new ultraviolet luminescent material and its application—Fluorescence properties of hBN single-crystal powder

Luminous properties of hexagonal boron nitride (hBN) single-crystal powder were studied by cathodoluminescence and photoluminescence spectroscopy. The single crystals grown by a high pressure and high temperature method showed typical excitonic spectra at peak wavelengths of 215, 220, and 227 nm at room temperature. Well-faceted hexagonal shaped single crystals exhibited the dominant 215-nm band. The 220- and 227-nm bands were singly or concurrently observed in the case of irregular-shaped crystal powders, though no discernible difference between the morphologies of crystal powders showing differently superimposed luminous spectral profiles of the 220- and 227-nm bands was observed. However, each band showed different spectral and decay features at 8 K, implying that the origins of the two bands are different.

Research highlights
► Luminous properties of hBN single-crystal powder were studied.
► The powder shows 3 excitonic bands, 215, 220, and 227 nm at room temperature.
► We study the relation between morphologies and the 220- and 227-nm excitonic bands.
► Each band showed different spectral and decay features.
► It implies that the origins of the two excitonic bands are different.