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Eu3+-doped SiO2–HfO2 glasses for optical applications were prepared using sol–gel technology. The effect of heat treatment on structure, emission properties and decay kinetics was investigated. The results show that the energy splitting of the 7F2 state of Eu3+ ions occurs for the samples sintered at temperatures >1000°C. This behavior can be explained by the fact that crystal phases are formed in those samples, which can be confirmed by X-ray diffraction analysis. Moreover, fluorescence line narrowing spectra for the samples sintered at different temperatures were measured, and the results were interpreted in terms of structural changes in the glass matrix and the Eu3+ bonding environment. [ABSTRACT FROM AUTHOR]

Europium-doped borophosphate glasses were prepared by the melt quenching method for application in light-emitting diodes. Emission spectra and electron paramagnetic resonance were studied for the glass samples. The relative intensity ratio of Eu2+ to Eu3+ emissions is composition dependent, especially the B2O3/P2O5 (B/P) ratio and the type of alkaline earth cations. The possible mechanisms are discussed. [ABSTRACT FROM AUTHOR]

Abstract: Eu2+ and Mn2+ co-doped (Sr,Ba)6BP5O20 phosphors were prepared by high temperature solid state reaction. Photoluminescence spectra and color-coordinate parameters were measured and effects of Ba2+ content on crystal structure and properties of phosphors were investigated. The results show that crystal structure of the phosphor is single phase of Sr6BP5O20-like. Excitation band of the phosphors covers wide region from 300 to 420nm. Two emission peaks at 420nm and 480nm and a red emission tail are in existence while the ratio of intensity between 420nm and 480nm are affected by the content of Ba2+. With the increasing content of Ba2+, color-coordinate parameters x, y change regularly, and lighting color moves from greenish blue, purplish blue to white. White-emitting phosphors were finally obtained with color-coordinate x, y of 0.223 and 0.237, respectively. [Copyright &y& Elsevier]