Interfacial Diffusion Inhibition through Glass Network Design in YAG:Ce3+ Phosphor-in-Glass Composites for High-Power Solid-State Lighting

Phosphor-in-glass (PiG) is a promising all-inorganic color converter for high-power solid-state lighting applications. However, strong interfacial diffusion degrades the phosphor performance and impedes the progress of PiG-based white light-emitting diodes (WLEDs) in achieving high brightness and efficacy. In this study, a glass matrix (SiO2–B2O3–Al2O3–CaO-Y2O3–Na2O) designed specifically for Y3Al5O12:Ce3+ (YAG:Ce3+) phosphors was proposed aiming to suppress interfacial diffusion. The glass design principles involved confining ionic diffusion through modulation of the glass coordination structure and reducing interfacial concentration gradients through introduction of phosphor elements into the glass matrix. Consequently, interfacial diffusion in the synthesized YAG:Ce3+-PiG was effectively suppressed, with an interfacial reaction layer thinner than 55 nm. The internal quantum efficiency of YAG:Ce3+-PiG was sustained at 97%, while its fluorescence lifetime decreased by only 0.6 ns compared to that of the original phosphor. The WLED fabricated with YAG:Ce3+-PiG exhibited a high luminous efficacy of 122 lm/W under a high input power of 3 W. Additionally, simultaneous incorporation of YAG:Ce3+ and CaAlSiN3:Eu2+ phosphors further enhanced the white-light quality of the WLED, achieving a high color rendering index of 92.6. The findings underscore the importance of rational glass composition design for PiG composites and will facilitate the development of efficient high-power WLED devices.