Investigation of the origin of atomic-like emission at 4.09 eV from h-BN by correlating PL and XPS spectra

Deep ultraviolet (UV) photoluminescence (PL) and x-ray photoemission spectroscopy (XPS) were employed to investigate the origin of the atomic-like emission line at 4.09 eV from hexagonal boron nitride (h-BN) single crystals. High resolution XPS spectra analyzed by correlating PL spectra of the h-BN samples with and without the sharp emission line at 4.09 eV showed that carbon is bonding to both boron and nitrogen in the sample that has the 4.09 eV emission line. Our results showed that the defect responsible for the origin of the 4.09 eV line from h-BN is carbon related and it suggests that the defect structure has elemental carbon occupying both boron (CB) and as nitrogen (CN) sites.