白光LED用球形Y_(2.96)Al_5O_(12):0.04Ce^(3+)荧光粉的制备及光致发光

Preparation and Photoluminescent Property of Sphere Y_(2.96)Al_5O_(12):0.04Ce^(3+) Phosphor for White Light-Emitting Diodes

采用水热-热解法制备了可用于实现白光LED的Y2.96Al5O12∶0.04Ce3+荧光粉,通过X射线衍射(XRD)、扫描电镜(SEM)、X射线能谱(EDS)及荧光光谱(PL)等对Y2.96Al5O12∶0.04Ce3+荧光粉的物相、形貌及光致发光性能进行了表征。结果表明:水热-热解法制备出了物相纯净、分散性良好的球形Y2.96Al5O12∶0.04Ce3+粉体,该荧光粉可被460nm蓝光有效激发,发射光谱为峰值在550nm的一宽带,且水热-热解法得到的YAG∶Ce3+粉体发射强度优于传统高温固相法合成的YAG:Ce3+荧光粉;通过积分球耦合荧光光谱仪对荧光粉与蓝光芯片配合所得白光LED的量子效率进行了测试,结果表明:水热-热解法制备的Y2.96Al5O12∶0.04Ce3+荧光粉绝对量子效率为88.40%,外量子效率为78.64%,色坐标为(0.453 8,0.531 8),色温为358 4K,该方法制备的Y2.96Al5O12∶0.04Ce3+荧光粉稳定性及数据测定的重现性较好,是一种适用于暖白光LED的高性能黄色荧光粉。

Cesium ions doped yttrium aluminum garnet(Y2.96Al5O12 ∶0.04Ce3+)phosphors for white light emitting diodes(WLED)were successfully prepared by hydrothermal-thermolysis method.The phase composition,morphology,and photoluminescent properties of the prepared powders were investigated by X-ray diffraction,scanning electron microscopy,energy-dispersive X-ray spectroscopy,and photoluminescence spectroscopy.The results indicated that the successful preparation of the pure Y2.96Al5O12∶0.04Ce3+powders are spherical particles and have good dispersibility.The phosphors were excited by the blue light with wavelength of 460 nm,and a broad peak at 550 nm was observed in the emission spectrum.Moreover,the emission peak intensity of the YAG∶Ce3+powders prepared by hydrothermal-thermolysis method was higher than that of the samples prepared by traditional high temperature solid state method.Furthermore,the quantum efficiency of the white LED produced by the phosphors and blue chip was measured by the integrating sphere coupled fluorescence spectrometer,and the results indicated that the absolute quantum efficiency and external quantum efficiency of Y2.96Al5O12∶0.04Ce3+phosphors prepared by hydrothermal-thermolysis method were 88.40% and 78.64%,respectively,with the color coordinates of(0.453 8,0.531 8)and the color temperature of 358 4K.The prepared Y2.96Al5O12∶0.04Ce3+phosphors exhibited excellent stability and repeatability,and acted as excellent yellow phosphors for warm white LED.