Preparation And Spectorseopic Properties Of Cu Doped Phosphosilicate Glasses

A series of phosphosilicate glasses containing Cu or Cu/Sn have been prepared via a melt-quenching method. The test measurements of differential thermal analysis (DTA), X-ray diffraction (XRD) analysis, transmission electron microscope (TEM), Raman spectra and photoluminescence (PL) were used to study the copper’s existing form and spectroscopy performance. In order to stabilize Cu+, the redox of Cu0(?) Cu+(?)Cu2+ in glass was regulated by introducing the reductant SnO and heat treatment.In the phosphosilicate glasses containing different content of Cu, Cu0 nanoparticles and Cu+were identified in the glasses with with low Cu concentrations (0.02; 0.04; 0.1 mol%), and Cu+ and Cu2+ were identified in the glasses with high Cu concentrations (0.2; 0.4; 0.6 mol%). The change of copper’s valence state in phosphosilicate glasses was related with the number of non-bridging oxygen and an increased number of non-bridgng oxygen right shifted the equilibrium of Cu0(?) Cu+(?)Cu2+. Therefore, increasing non-bridging oxygen concentration appropriately could be used to promote Cu0→Cu+ in the case of high Cu0 concentration.In the phosphosilicate glasses containing fixed Cu/Sn concentration doping ratio, introducing reductant SnO could effectively inhibited the oxidation of Cu+. Only when Cu/Sn codoping concentration increased to 1mol%, the Cu0 nanoparticles were formed in glass. The PL intensity increased firstly and then decreased with the increasing Cu /Sn codoping concentration, and reached the-maxium when Cu/Sn codoping concentration was 0.15mol%. In the phosphosilicate glasses containing different Cu/Sn concentration ration (Cu-doped content was fixed to 1 mol%), with the increasing content of Sn, the reduction reaction Cu2+→Cu+ took place firstly and the PL intensity of samples increased gradually. When Sn concentration increased to 0.6mol%, the PL intensity reached the maximum. Continuing to increase Sn doping amount, excess of Sn promoted the reduction reaction Cu+→Cu0 and then formed Cu0 nanoparticles, leading to the weakness of PL intensity.In the phosphosilicate glasses containing low fixed Cu/Sn doping concentration ratio (0.2 mol%), heat treatment promoted the reduction reaction Cu2+→Cu+. The higher heat treatment temperature, the Cu2+→Cu+ conversion degree and PL intensity were higher. In the case of high fixed Cu/Sn concentration doping (>0.2mol%), heat treatment promoted the reduction reaction Cu+→Cu0. The higher heat treatment temperature and Cu/Sn doping concentration, Cu0 nanoparticles formed larger and PL intensity was weaker. In the phosphosilicate glasses containing different Cu/Sn concentration ration (Cu-doped content was fixed to 1 mol%), relatively low temperature heat treatment could make all samples form Cu0 nanoparticles because of high Cu doping concentration.Studies have shown that improving non-bridging oxygen concentration could regulate the redox of Cu0(?) Cu+(?)Cu2+to right. Introducing the reductant SnO and heat treatment could left shift the redox of Cu0(?) Cu+% Cu2+. Thus, a combination of these three means were expected to achieve a heavily doped of Cu in phosphosilicate glass, and stabilize most of Cu as Cu+ to optimize visible broad spectrum of Cu+ doped phosphosilicate glass.