The YAG:Ce Phosphor Glass Prepared by a Low-Temperature Stirring Technique for WLED: Achieving High Luminous Efficiency of the Phosphor

Fluorescent glass (PiG) has emerged as an important candidate material in the field of white light-emitting diode (WLED) illumination. However, its conventional preparation processes are often complex and time-consuming, resulting in a significant performance degradation during fabrication. In this study, we carefully designed a SiO₂-P₂O₅-Al₂O₃-Na₂O-K₂O-BaO glass composition, which was combined with Y₃Al₅O₁₂:Ce³⁺ (YAG:Ce) phosphor via a low-temperature stirring process at 750 °C. This approach aims to minimize the thermal and structural damage to the YAG:Ce phosphor, yielding high-quality fluorescent glass (PiG). For comparison, a control sample (S-PiG) was fabricated using the traditional sintering process, in which glass powder and the same amount of YAG:Ce phosphor were sintered in a muffle furnace. X-ray diffraction and scanning electron microscopy analyses revealed that the mild synthesis method produced fluorescent glass with a uniform microstructure and an ideal crystalline phase, both contributing to the enhanced luminescent efficiency and optical performance. Subsequently, both PiG and S-PiG were coupled to blue LED chips to fabricate WLED devices, and their photoluminescent properties were systematically investigated. The results demonstrated that the newly developed PiG exhibits an excellent luminescent performance under blue-light excitation, achieving an internal quantum efficiency as high as 88.03%. Its emission spectrum covers the ideal white-light region, with a luminous efficacy (LE) of 157.43 lm/W, a correlated color temperature of 6097 K, and CIE chromaticity coordinates of (0.3340, 0.3524). These findings indicate that the low-temperature stirring process effectively preserves the luminescent properties of YAG:Ce phosphors within PiG. This not only highlights the importance of this technique in enhancing the performance of YAG:Ce-based fluorescent glass but also provides a novel and practical approach for future WLED lighting applications.