β-Sialon:Eu2+ phosphor-in-glass: An efficient and potential green color conversion material for laser lighting systems

Highlights: • β-Sialon-PiG have been successfully prepared and hold a good thermal stability. • β-Sialon-PiG has a high internal quantum efficiency of 72% after synthesis. • Under the 450 nm blue laser, higher luminous efficiency of 154 lm/W was obtained. • A high threshold of 363 lm of lumen flux was obtained for the sample under laser. -- Abstract: With the high demand of modern people for lighting quality, higher requirements have been put forward for the lighting technology. Compared with traditional light emitting diodes (LEDs), laser diode (LD)-driven lighting technology has more prominent advantages in the fields of industry, military and life. Here, we report a phosphor-in-glass (PiG) material formed by co-firing commercial β-Sialon:Eu²⁺ phosphor and SiO₂-Na₂CO₃-H₃BO₃-CaO (SNBC) glass. It is found that the powder perfectly dispersed in the glass without obvious interface reaction. Fluorescence intensity of PiG sintered at 800 °C is the strongest, and the position of the luminescence peak is around 540 nm. Then through the analysis of different concentrations of PiG phosphors, it is found that the internal quantum efficiency (IQE) can reach 72%. The specific heat capacity decreases with the increase of temperature, indicating that the heat dissipation effect is fine. Under the blue LD irradiation of 450 nm, the luminous flux of the PiG sample reaches 363 lm and the high luminous efficiency of 154 lm/W. Our research found that the prepared β-Sialon-PiG can provide green light for high-power laser illumination and is a stable and efficient fluorescent conversion material.