The authors report on the correlation between the photoluminescence (PL) property and the SnO amount in SnO-ZnO-P2O5 (SZP) glass. In the PL excitation (PLE) spectra of the SZP glass containing Sn2+ emission center, two S1 states, one of which is strongly affected by SnO amount, are assumed to exist. The PLE band closely correlates with the optical band edge originating from Sn2+ species, and they both largely red-shifts with increasing amount of SnO. The emission decay time of the SZP glass decreased with increasing amount of SnO and the internal quantum efficiencies of the SZP glasses containing 1~5 mol% of SnO are comparable to that of MgWO4. It is expected that the composition-dependent S1 state (the lower energy excitation band) governs the quantum efficiency of the SZP glasses.

These findings indicate that nitric oxide mediates neurotoxic actions of glutamate which are responsible for ischemic injury in the retina.

The authors report on the quantum efficiency (QE) of UV-excited photoluminescence measured in SnO–ZnO–P2O5 glass developed as rare earth (RE)-free material for light emitting diode (LED) applications; we report what is, to the best of our knowledge, the highest value of QE ever reported. It is notable that the QE value of the present RE-free glass (∼90%) is comparable to that of RE-doped glass. For future LED applications, we have emphasized that the low-melting glass will be one of the most industrially favorable inorganic materials to replace organic sealants that suffer degradation by strong LED irradiation.

Softening or melting behavior of the organically-modified siloxane hybrid gels and glasses in the system of RSiO3/2 and R2SiO2/2 (R: methyl and phenyl) has been investigated to obtain a new family of low-melting glasses. The RSiO3/2 and RSiO3/2–R2SiO2/2 gels showed softening temperatures around 50–100 °C. The softening temperature of RSiO3/2 single-component glasses, which were obtained by melting the corresponding gels at a temperature above the softening temperature, increased by heat-treatment at 200 °C, and finally showed no softening behavior. On the other hand, in the PhSiO3/2–Ph2SiO2/2 binary glasses, the softening temperatures showed a tendency to saturate after longer heat treatment over 200 h. These facts indicate that the present organically modified siloxane system will be a potential candidate for the low-melting glass.

Sn2+ centers exhibiting high quantum efficiency were observed in zinc phosphate glasses prepared under inert conditions.

Transparent inorganic luminescent materials have attracted considerable scientific and industrial attention recently because of their high chemical durability and formability. However, photoluminescence dynamics of ns2-type ions in oxide glasses has not been well examined, even though they can exhibit high quantum efficiency. We report on the emission property of Sn2+-doped strontium borate glasses. Photoluminescence dynamics studies show that the peak energy of the emission spectrum changes with time because of site distribution of emission centre in glass. It is also found that the emission decay of the present glass consists of two processes: a faster S1-S0 transition and a slower T1-S0 relaxation, and also that the energy difference between T1 and S1 states was found to be much smaller than that of (Sn, Sr)B6O10 crystals. We emphasize that the narrow energy gap between the S1 and T1 states provides the glass phosphor a high quantum efficiency, comparable to commercial crystalline phosphors.

No abstract

The authors have demonstrated white light emission of rare earth (RE)-free Mn-doped SnO-ZnO-P(2)O(5) glass. The RE-free glass shows white light emission with a high value of quantum efficiency (QE) comparable to conventional crystalline phosphor. It is notable that the high QE value is attained for RE-free transparent glass, and the broad emission can be continuously tuned by both the amount of activator and the composition of the glass. Since this glass possesses low-melting property, we emphasize that the glass phosphor will lead to the development of a novel inorganic white-light-emitting device in combination with a solid state UV light-emitting source.