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

Abstract 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.