Luminescence of localized states in oxidized and fluorinated silica glass

Abstract

Photoluminescence of nominally pure oxidized and fluorinated silica glasses, which have good optical transparency in the optical gap, has been investigated under excitation by excimer lasers. The data are compared with the data for chlorinated silica glass, as well as glass containing OH. The excitation of localized states provides the release and capture of charge carriers, despite the low absorption coefficient. The holes are self-trapped. The recombination in the thermally activated or tunnel process creates luminescence of oxygen-deficient centers. It is concluded that oxidation and fluorination do not change the concentration of localized states, but they change the electronic transitions of the localized states to higher energies. In type III glass with a high OH content, luminescence is suppressed by the presence of hydrogen and appears after irradiation with 7.9 eV photons of the F2 laser. This observation suggests the existence of localized states even in these glasses.

Sol–Gel Synthesis of Translucent and Persistent Luminescent SiO2@ SrAl2O4 Eu, Dy, B Materials

“…Transmittance spectra are similar for all samples; however, there are small differences in the shorter wavelength range; the local maxima in the range of 240–360 nm were more pronounced for the samples with higher boron concentrations (10 and 15%). It is known that the shape of the fundamental absorption edge in the exponential (Urbach) region is dependent on the disorder effects in the glass [ 46 , 47 ]. Therefore, we can conclude that excessive boron addition leads to a more disordered SiO 2 network.…”

Luminescence of ZnO nanocrystals in silica synthesized by dual (Zn, O) implantation and thermal annealing

“…To excite intrinsic defects in silica, electron beam (cathodoluminescence), γ-irradiation [30,39] or excimer lasers [42] are usually used. Second, based on results presented in [43], a high concentration of ODCs as well as NBOHCs is not to be expected after annealing at 750 • C for 120 min in air.…”