研究了传统白光LED与蓝光激发的球冠形远程荧光粉白光LED在不同电流、不同热沉温度下的发光性能, 并对其机理差异展开了探讨。实验结果表明: 随热沉温度和驱动电流的上升, 传统白光LED的量子效率和电光转换效率急剧下降, 并导致其Y/B比(Yellow/Blue Ratio)下降, 相关色温上升。而在远程荧光粉白光LED中, 其量子效率、光转换效率和相关色温在相同实验条件下变化幅度都较小。由光强空间分布和Y/B比空间分布可知, 远程荧光粉白光LED的光强分布呈类似蝠翼分布, 且Y/B比空间均匀性远大于传统白光LED。

Under different drive current and heat sink temperature, luminous performances as well as physical mechanisms were studied for both traditional phosphor-dispensing packaging white LED and blue light-converting hemisphere remote phosphor LEDs. With the increase of the heat sink temperature and the drive currents, the quantum efficiency and light conversion efficiency in the traditional phosphor-dispensing packaging white LED drop rapidly, which is responsible for the decrease of Y/B ratio (Yellow/Blue Ratio) and the apparent increase of CCT (correlated color temperature). However, the parameters of quantum efficiency, light conversion efficiency and CCT in blue light-converting hemisphere remote-phosphor packaging LEDs have little change under the same experimental conditions. In addition, the remote phosphor LEDs exhibit a batwing spatial luminous intensity distribution and the spatial Y/B ratio distribution is much more homogeneous compared with the traditional phosphor-dispensing packaging white LED.