Innovative Microstructure Design of Phosphor‐in‐Glass Film Converter for Efficient and High‐Brightness Laser Lighting

Abstract High‐brightness laser illumination faces crucial challenges in the development of color converters with efficient heat dissipation and luminous efficiency (LE). Herein, an innovative microstructure design of a phosphor‐in‐glass film (PiGF) coated on a sapphire color converter (M‐PiGF@S) is designed and prepared by adopting the hot‐press bonding and low‐temperature sintering strategies. By optimizing the PiGF thickness, the M‐PiGF@S (110 µm) converter enables a high‐luminance white light with a high luminous flux (LF) of 5877 lm under a maximum laser power density saturation threshold (LPD‐ST) of 39 W mm ⁻² , which is 179.5% of the traditional PiGF@S converter with a LF of 3274 lm@21 W mm ⁻² . Compared to the PiGF with double‐sided sapphires (S@PiGF@S), the maximum LF of M‐PiGF@S are increased by 13.72%, and it also demonstrates a higher overall LE level, with the maximum improvement reaching 16.86% under 7 W mm ⁻² . The research results have demonstrated that the new structure of the color converter has great potential for efficient and high‐brightness laser lighting.