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

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.