A unique coating film architecture makes Ce:YAG sapphire films suitable for high-power laser-driven lighting

The field of solid-state laser illumination is developing rapidly. Phosphor-in-glass film (PiF) has been proved to be a promising color-conversion material for high-quality laser illumination due to their excellent chromatic properties, tunability, and simple fabrication process. However, conventional fabrication methods that fix the phosphor layer directly onto small-sized therally conductive substrate struggle to simultaneously achieve both high luminous flux and high luminous efficiency. In this study, Ce:YAG PiF@Coating film (PiF@CF) was obtained by coating Ta 2 O 5 composite film on the surface of sapphire substrate which was not coated with phosphor layer through a unique coating film design. The coated Ce:YAG PiF@CF achieves synergistic optimization of luminous efficiency (LE) and luminous flux (LF). While achieving a laser performance of 243.63 lm/W peak LE and holding 1641 lm @ 8.32 W, which is twice that of the uncoated Ce:YAG PiF (824.63 lm). In addition, the sample maintains an excellent thermal conductivity of 12.92 W/(m K) at 573 K. This study provides a new solution for high-power laser illumination fluorescence conversion materials that take into account the three aspects of luminous efficiency, luminous flux and heat dissipation performance through the coating process, laying an important foundation for its application in the fields of lighting and display.