Nanotechnology. 2022 Feb 7. doi: 10.1088/1361-6528/ac5283. Online ahead of print.
ABSTRACT
Two-dimensional hexagonal boron nitride (h-BN) materials have garnered increasing attention due to its ability of hosting intrinsic quantum point defects. This paper presents a photoluminescence (PL) mapping study related to sub-bandgap-level emission in bulk-like multilayer h-BN films. Spatial PL intensity distributions were carefully analyzed with 500-nm spatial resolution in terms of zero phonon line (ZPL) and phonon sideband (PSB) emission-peaks, and their linewidths, thereby identifying the potential quantum point defects within the films. Two types of ZPL, and PSB emissions were confirmed from the point defects located at non-edge- and at the edge of the films. Our statistical PL data revealed consistent broad and relatively narrow emission from the non-edge and edge area of the sample, respectively. The measured optical properties of these defects and the associated ZPL peak shift and line broadening as a function of temperature between 77° and 300°K are qualitatively and quantitatively explained. Moreover, an enhancement of the photostable PL emission by at least a factor of ×3 is observed when our pristine h-BN was irradiated with a 532 nm laser.
PMID:35130530 | DOI:10.1088/1361-6528/ac5283
