Preparation And Luminescence Properties Of Sm³⁺/Tb³⁺ Doped Na₃Y（PO₄）₂ Crystal Glass Ceramics

At present,commercial white light-emitting diodes（w-LEDs）use chips to excite the phosphor to obtain white light,but the phosphor mixed in epoxy resin will be deteriorated and turn yellow under high temperature and energy excitation.Therefore,it is necessary to choose a new type of light-emitting substrate-glass ceramics,which has similar transparency to glass and single crystals,can reduce the loss of light through,improve the luminous efficiency and other advantages have attracted wide attention.Sm³⁺single-doped,Tb³⁺single-doped,Sm³⁺/Tb³⁺co-doped glass ceramics containing Na₃Y（PO₄）₂crystal phase were prepared by the melting-crystallization method.Combined differential scanning calorimetry curve,X-ray diffraction,scanning electron microscope and light transmittance curve,the heat treatment systems of Sm³⁺single-doped,Tb³⁺single-doped,Sm³⁺/Tb³⁺co-doped glass ceramics were determined as follows:660°C、120min,660°C、120min,650°C、60min.According to the excitation and emission spectra,the fluorescence intensity of glass ceramics with different concentrations of Sm³⁺and Tb³⁺doping was taken into account,which the optimal concentration of Sm³⁺,Tb³⁺doping was determined to be 1.2%and 2.0%,and the concentration optimal double-doped Sm³⁺/Tb³⁺was2.0%-2.0%.It can be seen from the fluorescence spectrum that the phenomenon of concentration quenching has occurred,and the reason for the concentration quenching based on the critical distance is multi-level interaction.The fluorescence lifetimes of Sm³⁺single-doped,Tb³⁺single-doped,and Sm³⁺/Tb³⁺co-doped glass ceramics were calculated using formulas.By analyzing the fluorescence spectrum and fluorescence lifetime of Sm³⁺/Tb³⁺double-doped glass ceramics,which it was proved that the energy transfer occurred in Tb³⁺→Sm³⁺,and the energy transfer efficiency was calculated.By adjusting the doping concentration of Tb³⁺and Sm³⁺,a coordinated emission of green light to cool white light can be achieved.Therefore,under certain conditions,Sm³⁺/Tb³⁺double-doped glass ceramics can achieve white light emission.