Studies of Phosphor Concentration and Thickness for Phosphor-Based White Light-Emitting-Diodes
Studies of Phosphor Concentration and Thickness for Phosphor-Based White Light-Emitting-Diodes
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DOI：
10.1109/jlt.2008.917087
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发表时间：
2008-11-01
影响因子：
4.7
通讯作者：
Shi, Frank G.
中科院分区：
文献类型：
--
作者：
Tran, Nguyen T.;Shi, Frank G.
采用三维光线追迹法模拟研究了大功率白色发光二极管（WLED）灯的光效与荧光粉浓度和厚度的关系。模拟表明，WLED灯的亮度或发光效率高度依赖于荧光粉浓度和荧光粉厚度（或荧光粉基质复合物体积）的组合。具有较低浓度和较高磷光体厚度的封装具有较高的发光效率，因为光捕获效率随着磷光体浓度的降低而降低。在4000 K左右的相关色温（CCT）值，光线跟踪模拟和实验结果表明，流明分别提高了20%和23%，与1.8 mm的荧光粉封装超过0.8 mm的荧光粉封装。具有凸透镜的封装可以比平透镜提高流明输出，但是这种提高很小，并且它需要更高量的磷光体，高达25%，以实现相同的CCT值。
The dependence of luminous efficacy on phosphor concentration and thickness for high-power white light-emitting-diode (WLED) lamps is investigated by employing three-dimensional ray-tracing simulations. The simulations show that the brightness or luminous efficacy of WLED lamps highly depends on the combination of phosphor concentration and phosphor thickness (or phosphor-matrix composite volume). The package with lower concentration and higher phosphor thickness has higher luminous efficacy because the light trapping efficiency is lower with the low phosphor concentration. At the correlated color temperature (CCT) value of around 4000 K, ray-tracing simulation and experimental results show 20% and 23% improvement in lumen, respectively, with a 1.8-mm-phosphor package over a 0.8-mm-phosphor package. A package with convex lens can improve the lumen output over flat lens, but this improvement is small, and it requires higher amount of phosphor, up to 25%, to achieve same CCT value.