摘要
研究了在蓝光芯片加黄色荧光粉制备白光LED方法中,色坐标位置对光通量的影响。在同样蓝光功率条件下,我们对标准白光点(色坐标x=0.33±0.05,y=0.33±0.05)附近不同色坐标位置的光通量进行了计算。假设(0.325,0.332)位置流明效率为100 lm/W,计算得出,最大光通量对应的色坐标位置为(0.35,0.38),光通量为112 lm;最小光通量对应的色坐标位置为(0.29,0.28),光通量为93.5 lm。相对于100 lm的变化幅度达到18.5%。通过与实验数据的对比和分析,进一步验证了白光LED光通量随色坐标增大而增加的这一趋势。
In this article, all the white LEDs are obtained from the GaN-based blue emitter plus a cerium doped yttrium aluminum gargnet （YAG：Ce） phosphor. Here we brought up a new method. Under certain ideal condition, we have rough estimated the color coordinates and the luminous flux about the white light LEDs with the new method. The color coordinates of the referenced white spectrum is （0. 325,0. 332）, the color rendering index is 81.5 and the color temperature is 5 914 K. All the parameters of the referenced white spectrum are similar to the standard white LED spectrum of （0.33, 0.33 ）. Based on the referenced spectrum, we simulated it and got the radiation intensities of the blue chip and the phosphor independently. By adjusting the proportion of the radiation intensities of the blue chip and the phosphor, we got some new white LED spectra. And here we defined the luminous flux of the referenced spectrum is 100 lm and the total photons of all the white LEDS is equal to the referenced white LED spectrum. Also the conversion efficiency is supposed to 100%. In the range of （x,y） = [0. 33,0.33] （＋0.05）, we calculated the luminous flux of different color coordinates around the standard point. We find that the color coordinate of the maximum luminous flux is at （0.35,0.38）and the luminous flux is 112 lm, the color coordinate of the minimum luminous flux is at （0.29,0.28）and the luminous flux is 93.5 lm. So we can know that the luminous flux dispersion can reach about 18.5% relative to the referenced point 100 lm. From the above results, when the luminous flux becomes the main parameter of all the white LEDs＇parameters, we can know that if we want to get higher luminous flux white LEDs, we should control the quantity of the phosphor to make the color coordinate around the point （0.35, 0.38）. Another experiment has been done too in this article. According to the data in the experiment, the changing trend that the luminous flux increases with the increasing of color coordinate is inos- culated to the calculated results. And we also find that the luminous flux dispersion 28.1% is much larger than the calculated result, so the controlling of the color coordinate becomes more important. The main reasons of the different dispersions between theoretical calculation and experiment have been concluded as follows： First, the quantum conversion efficiency is supposed to 100% in the calculation, but it can＇t reach in the experiment. Second, the blue chips are different types and even they are from the same silicon slice, they can＇t be the same completely. Third, the unavoidable errors that exist in the experiment influence on the results.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2007年第5期736-740,共5页
Chinese Journal of Luminescence
关键词
白光LED
光通量
色坐标
white light LED
luminous flux
color coordinate
