Integrating High Efficiency and Thermal Reliability Photoluminescence in Double‐Sapphire‐Sandwiched Phosphor‐in‐Glass Film for Laser Projection Displays

Abstract Laser projection display technology (LPDT), as next‐generation visual system, has been prized for the ultrawide color gamut and operational stability. However, thermal degradation under laser irradiation and the scarcity of efficient narrow‐band emitters are always challenging in LPDT. Herein, a double‐sapphire‐sandwiched phosphor‐in‐glass film (PiGF) based on commercial red‐emitting K ₂ SiF ₆ :Mn ⁴⁺ and green‐emitting β ‐SiAlON:Eu phosphors, is designed and prepared by a rapid sintering method. The as‐prepared PiGF demo can achieve high luminous flux of 3765 and 1365 lm, respectively, and the ingenious cooperative rotating dynamic heat dissipation mechanism maintains temperatures at 60 °C even under 14 W mm ⁻² laser irradiations, thereby preventing degradation. Once being integrated into a multicolor phosphor wheel, it generates noncoherent white light covering 125% of the Rec.709 color standard representing an ultrawide color gamut. This work provides an advanced phosphor material platform enabling high‐brightness, reliable LPDT for next‐generation projectors and televisions.