Electroluminescent Properties of WLEDs With the Structures of Ce:YAG Single Crystal/Blue Chip and :/Ce:YAG Single Crystal/Blue Chip

摘要

In this work, evidence for matching blue chips with Ce:YAG single crystal phosphor is given. Forward current () and red phosphor were investigated and discussed to improve the electroluminescent properties of WLEDs using Ce:YAG single-crystal phosphors. Optimum forward current of such a device is chosen at above 45 mA. The structure of : phosphor/Ce:YAG single crystal/blue chip enormously improved the color temperature and color rendering index. This method can be a solution to achieve warm white light. The chromaticity of this structure with the color temperature of 5629 K and color rendering index of 77.1 is closely meeting the demand for ideal white light for general lighting (0.33, 0.33), but the luminous efficiency () is lower at 81.04 lm/W in comparison to that of the Ce:YAG single crystal/blue chip structure at 94.55lm/W.