Study On The Preparation And Properties Of Rare Earth And Transitional Metal Ions Doped Oxide Luminescence Glasses

As a green lighting source,light emitting diode?LED?has the advantages of energy saving,long life,environmental friendly,and shows great application prospect.Luminescence glasses possess good thermal stability and are easy to process into various desired shapes.The luminescent glass can be directly packaged with the LED semiconductor chip without using epoxy resin.The thermal conductivity of the luminescence glass is higher than that of epoxy resin.Thus the heat of the semiconductor chip can be dissipated easily during the working of W-LED,and the temperature of the PN junction of the semiconductor chip is reduced accordingly.Based on this background,we investigated the rare earth and transitional metal ions doped oxide glasses.A series of luminescent glasses were prepared via melt quenching technique,suchasPr dopedoxyfluoridesilicateglasses,Eu/Dydoped borophosphosilicate glasses,Tb/Sm doped phosphosilicate glasses,and Ag doped oxyfluoride silicate glasses.The as-prepared glasses were studied using absorption spectra,luminescence spectra,color coordinate,decay curves,X-ray diffraction,Fourier transform infrared?FT-IR?spectra.For the Pr doped oxyfluoride silicate glasses,we find that that replacing CaO with Na₂O and increasing the content of Al₂O₃ can promote the spontaneous crystallization of CaF₂ and Al₂O₃ in glass,respectively.The addition of Al₂O₃ in glass composition can enhance the ³P₀-³H₄?481 nm?emission of Pr³⁺ions,whereas B₂O₃ have the adverse effect.The reabsorption of Pr³⁺at 481 nm is observed using the excitation wavelength of 443 nm,which can be strengthened with the increase of CaF₂ crystal content.For the Eu/Dy single or co-doped aluminoborophosphosilicate glasses,the relative content of B₂O₃/P₂O₅ has a significant influence on the change of glass structure and the regulation of Eu and Dy luminescence.The AlPO₄ crystal can be formed during the process of melting and quenching without any further heat treatment for nucleation and crystallization.For the glasses prepared in the air atmosphere,Eu³⁺can be spontaneously reduced to Eu²⁺.The conversion efficiency,luminescence properties and glass structure depend greatly on the relative content of B₂O₃/P₂O₅.The energy transfer of Eu²⁺to Dy³⁺was discussed by fluorescence decay analysis.The luminescent color of the glasses are effectively controlled by changing the content of B₂O₃/P₂O₅ and the level of Eu ion doping.For the Eu/Dy doped calciumborophosphosilicate glasses,the formation of NaCa₅?PO₄?₅ crystal can be enhanced by increasing B₂O₃ and reducing P₂O₅ contents.In the Tb/Sm doped phosphosilicate glasses,the formation of phosohate crystals can be inhibited by the introduction of Al₂O₃ and CaO,whereas Na₂O can promote the formation of crystals.The partial conversation of Na₃Ca₆?PO₄?₅ to NaCaPO₄ occurs with increasing Na₂O and reducing Al₂O₃ contents.The bending vibration of[PO₄]^3-in 630–540 cm^-11 is increased with the formation of phosohate crystals.The relative emission intensity of Tb³⁺and Sm³⁺can be adjusted via the change of excitation wavelength due to the overlap of the excitation bands of Tb³⁺and Sm³⁺.In the Ag doped oxyfluoride silicate glasses.The replacement of CaO with Na₂O in the glass facilitates the precipitation of ZnAl₂O₄ crystals.The variation of Ag⁺doping amount and the glass matrix composition cause the shift of Ag⁺emission peak.Furthermore,the increase in Ag⁺content promotes the reduction of Ag⁺to Ag⁰ in a particular glass composition.The coupling between Ag⁺and Ag⁰ produces new excitation absorption and emission behavior in the glasses.