A Universal PiGF@Sapphire@MiG Color Converter with Synergistically Enhanced Opto-Thermal Performance for Laser-Driven Applications

High-power laser-driven projection display demands that the phosphor converters possess excellent thermal handling capacity and stably efficient light output; however, simultaneously enhancing opto-thermal performance is still full of challenges. Herein, a novel universal architecture of phosphor-in-glass film (PiGF) on sapphire substrate with MgO-in-glass (MiG) layer coated on the other side is developed. Owing to the high refractive index of 1.74 and thermal conductivity of 50 W·m −1 ·K −1 of MgO, the MiG layer not only recycles the backscattering light but also improves the heat dissipation, leading to synergistically enhanced opto-thermal properties of PiGF. Taking Y 3 Al 5 O 12 : Ce 3+ (YAG) PiGF-sapphire-MiG (YSM) as a representative example, the optimized composite enables a high luminous flux (LF) of 5515 lm and luminous efficiency (LE) of 196.9 lm·W −1 at a luminescence saturation threshold (ST) of 28 W·mm −2 . After introducing red-emitting CaAlSiN 3 : Eu 2+ (CASN) component, the YAG-CASN PiGF-sapphire-MiG (YCSM) converter yields warm white light with a color rendering index (CRI) up to 90.6, enabling to realization of more details and more vivid color rendition of the laser projection system. This study provides a cost-effective, easy-prepared, and universal strategy for advancing high-efficiency PiGF-based color converters and high-power laser-driven applications.