Defect-induced blue luminescence of hexagonal boron nitride

Enhancement of the deep-level emission and its chemical origin in hexagonal boron nitride

“…2(a), even leading to the maximum internal quantum efficiency of $50% for the entire emission spectrum. Previously, several researchers 10,21,22,43 also reported the structured emission spectra in the NUV region below $3.5 eV under excitation with photons of $4 eV energy (or higher). In these previous works, 10,21 the structured NUV bands were simply interpreted in terms of the higher order phonon replicas of the 4.1-eV ZPL.…”

Defect assisted optical limiting performance of hexagonal boron nitride nanosheets in aqueous suspension and PMMA nanocomposite films

“…3 inset shows the emission spectra of the h-BNNS dispersion under 6.20 eV excitation energy. A structured broadband between 300 and 450 nm is observed and in literature it is attributed to the radiative recombination of deep donor-acceptor pairs resulting from defects of boron-nitrogen vacancies and carbon-oxygen impurities occupying the vacancies [23,38,39]. While it is not possible to obtain an estimation of band gap energy from PL emission spectra because radiative recombination occurs via defect levels and yields emission energies much lower than band gap energy, excitation spectra can be used to estimate band gap energy by obtaining excitation wavelength where the maxima of PL emission band (350 nm) demonstrates a sharp increase.…”

Light-emitting properties of BN synthesized by different techniques

“…One more aspect of the increasing attention to nano-BN is related with its light-emitting properties [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. It is known that bulk hexagonal boron nitride, being excited either by accelerated electrons beam or by far UV radiation, is a good light emitter in deep ultraviolet [7][8][9].…”

“…Bulk h-BN is also fluorescent in the visible range under optical excitation above 4 eV [10][11][12], which makes h-BN material suitable for creation of display and lighting devices. Visible luminescence of bulk BN forms a wide phonon-assisted emission band with asymmetric profile: it peaks in the violet-blue region and has a long tail to the low energy side ranging to green-orange region [13][14][15]. Visible luminescence can be excited either via band-to-band excitation or via defect-related intraband states [13,14].…”

“…Visible luminescence of bulk BN forms a wide phonon-assisted emission band with asymmetric profile: it peaks in the violet-blue region and has a long tail to the low energy side ranging to green-orange region [13][14][15]. Visible luminescence can be excited either via band-to-band excitation or via defect-related intraband states [13,14].…”