A Novel PiGF@Diamond Color Converter with a Record Thermal Conductivity for Laser‐Driven Projection Display

Abstract High‐brightness laser lighting is confronted with crucial challenges in developing laser‐excitable color converting materials with effective heat dissipation and super optical performance. Herein, a novel composite of phosphor‐in‐glass film on transparent diamond (PiGF@diamond) is designed and fabricated via a facile low‐temperature co‐sintering strategy. The as‐prepared La₃Si₆N₁₁:Ce³⁺ (LSN:Ce) PiGF@diamond with well‐retained optical properties of raw phosphor shows a record thermal conductivity of ≈599 W m⁻¹ K⁻¹, which is about 60 times higher than that of currently well‐used PiGF@sapphire (≈10 W m⁻¹ K⁻¹). As a consequence, this color converter can bear laser power density up to 40.24 W mm⁻² and a maximum luminance flux of 5602 lm without luminescence saturation due to efficient inhibition of laser‐induced heat accumulation. By further supplementing red spectral component of CaAlSiN₃:Eu²⁺ (CASN:Eu), the PiGF@diamond based white laser diode is successfully constructed, which can yield warm white light with a high color rendering index of 89.3 and find practical LD‐driven applications. The findings will pave the way for realizing the commercial application of PiGF composite in laser lighting and display.