Synthesis And Photoluminescence Properties Of Phosphor Based On Sr2CeO4with Dopants Of Rare Earth Ions

White light-emitting diodes (LEDs) have widely used in all kinds of fields, for example, indicators, backlights, automobile headlights and general illuminations. Owing to unique advantages in energy conservation and long lifetime, white LEDs will replace traditional light source in future. Phosphor is one kind of key material for fabrication of white LED, which determines performance of white LED. Therefore, the research on phosphor for white LED is very important. Hence, a series of phosphor based on Sr2CeO4with single dopants and co-doping of Eu3+and Dy3+were prepared in this article. And, their luminous mechanisms were studied by spectral analysis.(1) The Sr2Ce04phosphors were prepared by high temperature solid method and polymer network gel method. From XRD spectra, it was gained that simpler structure and purer Sr2Ce04phosphor can be prepared by polymer network gel method relative to high temperature solid method. Light emission of matrix Sr2Ce04originated from charges transfer of Ce4+-O2-in its crystal structure.(2) Sr2Ce04phosphor with single dopant of Eu3+(Sr2CeO4:Eu3+) was synthesized for future application in UV-LED or near UV-LED. The results show that light emission of Sr2Ce04:Eu+derived from both charges transfer of Ce-O in matrix Sr2Ce04and energy transfer from Sr2CeO4to Eu3+. When doped by Eu3+, the light color of Sr2Ce04changed distinctly, which varied from blue-white to red. Hence, it can be forecasted that lowering concentration of Eu3+will induce purer white light emission of Sr2CeO4:Eu3+phosphor.(3) Sr2Ce04phosphor with single dopant of Dy3+(Sr2CeO4:Dy3+) was synthesized. In the fluorescence emission spectra, it can be seen that Sr2CeO4:Dy3+exhibits double luminescence centers, the blue-light and red-light centers originated from Sr2Ce04and Dy+, respectively. And, intensities of above two light centers can be tuned by adjusting doping concentration of Dy3+When it increased, the quenching phenomenon of Sr2Ce04got remarkable, which can be explained by mechanism of electric quadruple-electric quadruple interaction.(4) Sr2Ce04phosphor with co-dopants of Eu3+and Dy3+(Sr2CeO4:xEu3+, yDy3+) was synthesized future utilization in UV-LED or near UV-LED. The results show that varying of concentrations of Eu3+and Dy3+in a certain range had little influence on crystal structure. From fluorescence emission spectrum, it can be seen that Sr2Ce04:xEu3+, yDy3+expressed main peaks of Sr2CeO4, Eu3+and Dy3+. The luminescence of co-doped Sr2CeO4phosphor is due to energy transfers of Eu3+-Sr2Ce04and Dy3+-Sr2Ce04. With Eu3+doping concentration of1mol%and Dy3+doping concentration of0.6mol%, the color coordinates of Sr2Ce04:xEu3+, yDy3+reached to (0.39,0.37), which is expected to be an ideal phosphor for white LED.