SR-excited luminescence of corundum with native defects

Low-temperature spectroscopic and scintillation characterisation of Ti-doped Al2O3

“…The spectral and kinetic characteristics of the UV emission band detected in Al 2 O 3 -Ti by us are very similar to what has been reported by Syudro et al [41]. Additionally, as can be seen in Fig.…”

“…Note that the decay time constant of the 325 nm emission band associated with the luminescence of F + centres amounts to a few nanoseconds [37,38]. Therefore the 290 nm band was tentatively attributed to exciton emission [41]. Recently, Kirm et al [30] detected a fast emission component in this spectral region (luminescence band centred at 3.77 eV) that can be selectively excited in the narrow range just below the energy gap of the crystal.…”

“…On the other hand, when examining luminescence of the pure Al 2 O 3 excited by synchrotron radiation, Syudro et al [41] managed to resolve the emission bands at 290 nm ($4.2 eV) and 325 nm ($3.8 eV) with different decay kinetics. At T ¼ 300 K the 290 nm emission band demonstrates two decay components, viz.…”

Efficient and tuneable photoluminescent boehmite hybrid nanoplates lacking metal activator centres for single-phase white LEDs

“…Luminescent metal oxide nanoparticles may offer a possible alternative to meet the material demand for ultraviolet-pumped WLED, mainly because of their high stability, simplicity, low toxicity and low cost. The fluorescence properties of Al 2 O 3 or g-AlOOH (boehmite) nanoparticles have already been studied [26][27][28][29][30][31][32][33][34][35][36][37][38] . For instance, these nanoparticles present emission in the ultraviolet and blue spectral regions due to lattice anion vacancies (F and F þ centres or grouping of these two defects) [30][31][32][33][34][35][36][37][38] excited through absorption of anionic vacancies below 300 nm, mismatching the pumped wavelength (350-420 nm) of commercial ultraviolet chips [26][27][28][29][30][31][32][33][34][35][36][37][38] .…”

Defects in Ce 3+ doped Y 2 SiO 5

“…One should neither forget the increased stability of the lattice when the positive, with respect to the environment, oxygen vacancies are filled with electrons. The F colour centres have usually very fast emission [10] so the origin of the ms range luminescence can not be directly related to the F centres.…”