Highly thermally stable red phosphor-in-glass films for high-power laser lighting

The development of CASN (CaAlSiN3: Eu2+) fluorescent materials with excellent quantum efficiency and low thermal quenching performance is an effective way to improve the quality of white light. In this research, a CASN-PiG film with a high external quantum efficiency (56%) and high thermal conductivity (12.935 W m−1 K−1) was prepared by co-firing CASN phosphors and glass powder on a sapphire substrate. The surface structure and optical properties of the CASN-PiG (phosphor-in-glass) film were studied in detail. Furthermore, the CASN-PiG film can even survive 5.3 W/mm2 blue laser excitation. Surprisingly, the blue laser diode is combined with the CASN-PiG film to obtain a high luminous flux of 164 lm. Importantly, the CASN phosphors is compounded with Ce:YAG phosphors to prepare a high CRI (85) PiG film with a luminous flux of 845 lm and a luminous efficiency of 190 lm/W, realizing high-quality white laser lighting.