用黄色和橙色硅酸盐荧光粉制备了白光LED, 调整黄粉和橙粉的比例得到不同的色温。 对样品进行光学测试, 发现黄粉与橙粉的比例小于7时, 黄光部分的峰值约590 nm, 比例大于7时, 黄光部分的峰值约570 nm; 显色指数和流明效率都是随色温的增大先上升后下降, 5 521 K时达到最优值, 这是由于低色温时, 荧光粉的浓度大导致不能有效激发, 光谱中红色成分过多导致显色指数低, 高色温时, 荧光粉浓度小导致蓝光不能有效利用, 光谱中红色成分过少导致显色指数低。 对样品进行10～80 ℃的变温测试, 发现流明效率降低并且幅度不同, 除了芯片本身的俄歇复合外, 还说明黄色和橙色荧光粉随温度上升激发效率下降程度不同, 橙色荧光粉的温度特性要优于黄色荧光粉。

White powder light emitting diodes (LED) with different color temperature were made by using different ratio of yellow to orange silicate phosphor. When the ratio of yellow to orange phosphor was less than 7, the peak wavelength of yellow light in spectra was about 570 nm and the wavelength was about 590 nm as the ratio was greater than 7. With the color temperature increasing, the color rendering index and the luminous efficiency increased at the beginning and then decreased. And color temperature of 5 521 K is the optimal value. The reason was the ineffective excitation of blue light due to higher concentration of phosphor and excess red light in spectra. In contrast, blue light was not excited effectively and red light in spectra was little when the color temperature was higher than 5 521 K. The luminous efficiency was decreased, and the decreased magnitude was inconsistency with the testing temperature from 10 to 80 ℃. This suggests that, besides Auger recombination, the decrease in excitation efficiency of yellow and orange phosphors is different as the temperature rises and orange phosphor’s temperature characteristic is superior to that of yellow phosphor.