WANG Guilu ^{1, 2}, KONG Yuqiang ^{1 ,2}, ZHU Yonggang ^{1, 2}, ZHENG Xigui ^{1, 2}, LU Yanna ^{1 ,2}, MA Yuelong ^{3, 4}, QI Xingyu ³, HAO Yongxing ^{1, 2}
(1. School of Mechanical Engineering, Zhengzhou University of Science and Technology, Zhengzhou 450064, Henan, China; 2. Henan Province Engineering Research Center of Digital & Intelligent Equipment, Zhengzhou University of Science and Technology, Zhengzhou 450064, Henan, China; 3. School of Mechanical and Electrical Engineering, Henan University of Technology, Zhengzhou 450001, Henan, China; 4. Songshan Laboratory, Zhengzhou 450046, Henan, China)

Abstract: Laser lighting has shown enormous potential in various fields, such as automotive lighting, military reconnaissance and projection display, due to its advantages of high brightness, small size and long illumination distance. However, phosphor in glass (PIG) has the problem of balancing high color rendering index (CRI) and high luminous flux (LF). Therefore, a composite PIG containing yellow phosphor (YAG:Ce³⁺) and red phosphor (CASN:Eu²⁺) was prepared. The internal quantum efficiency (IQE) of the prepared YAG:Ce³⁺ PIG is as high as 90.50% (95.4% of the original phosphor) and the luminous intensity at 150 ℃ is 93.3% of that at room temperature. After encapsulating YAG: Ce³⁺ with a mass percentage of 10 wt.% PIG and LD, the maximum LF obtained is 3479.2 lm. The LF of 7 wt.% CaAlSiN red PIG under 7.8 W laser excitation is 413 lm. By optimizing the ratio in the composite PIG, the maximum CRI of the laser device is 82.2, the correlation color temperature (CCT) is 4281 K, the luminous efficiency (LE) is 171.2 lm·W⁻¹ and the LF is 2036.6 lm with the combination of 10 wt.% YAG:Ce³⁺ and 7 wt.%CASN:Eu²⁺. Meanwhile, high CRI and high LF of PIG-based laser devices are realized. Therefore, PIG with homogenous structure combination is regarded as a potential phosphor conversion material.
Key words: laser lighting; color rendering index; luminous flux; phosphor in glass; composite structure