High-performance glass phosphor for white-light-emitting diodes via reduction of Si-Ce 3+ :YAG inter-diffusion

A novel Ce3+:YAG doped sodium glass (CeYDG) with low-melting temperature of 693°C and high internal quantum yield of 68% for white-light-emitting diodes (WLEDs) is demonstrated. The glass phosphor possesses glass transition temperatures of 578°C which exhibits a better thermal stability to overcome the thermal limitation of conventional Ce3+:YAG doped silicone due to low thermal stability of around 150°C. To the best of authors’ knowledge, this is the highest quantum yield yet reported for thermally stable glass phosphors. The high quantum yield is achieved by lowering the sintering temperature of 700°C for glass phosphor, which substantially reduces Si-Ce3+:YAG inter-diffusion, evidenced by high-resolution transmission electron microscopy (HRTEM). This new CeYDG with high-quantum yield is essentially beneficial to the applications for next-generation solid-state lighting in the area where high power and absolute reliability are required and where silicone simply could not stand the heat or other deteriorating factors due to its low thermal stability.