Chip-level Ce:GdYAG ceramic phosphors with excellent chromaticity parameters for high-brightness white LED device
Xiaoqian Xi, Le Zhang, Jian Kang, Yanbin Li, Zhongying Wang, Bin Fei, Xin Cheng, Guocan Huang, Ming Li, Hao Chen
Abstract
Development of ceramic phosphors (CPs) featuring small volume and high efficacy is crucial for miniaturization of white LEDs and their integration in solid state lighting. In this study, the chip-level 2.5×2.5 mm Ce:GdYAG CPs with different thicknesses were packaged to the blue chips, and their luminous characteristics were analyzed under the different radiant flux. Notably, when thickness of the CPs was 1.4 mm, a luminous flux of 2000 lm, a correlated color temperature (CCT) of 6266 K and a color rendering index (CRI) of 70 were obtained under 11.0 W blue power (1.76 W/mm 2 ) excitation. Phenomenon of colorimetric drift was explained simultaneously. These results indicate that Ce:GdYAG CPs is a promising candidate for automotive lighting and high-speed rail lighting.