Toward High‐Quality Laser‐Driven Lightings: Chromaticity‐Tunable Phosphor‐in‐Glass Film with “Phosphor Pattern” Design

Abstract

Abstract High‐quality laser‐driven lightings require not only high luminous flux (LF) but also uniform spectral distribution. Herein, the green‐emitting Lu 3 Al 5 O 12 :Ce 3+ (LuAG:Ce) and red‐emitting CaAlSiN 3 :Eu 2+ (CASN:Eu) commercial phosphor powders with high‐performance are fabricated into phosphor‐in‐glass film (PiGF) sintered on sapphire plate, and further served as a motor‐driven rotatory “phosphor wheel” to receive pumping of blue laser in a reflective excitation light path. The greatly relieved thermal pressure, benefited from the high‐thermal‐conductivity sapphire substrate and the pulse‐like rotatory excitation mode, efficiently retards the occurrence of luminescence saturation. Remarkably, the photon reabsorption phenomenon in the conventional “phosphor mixture” design is well solved by introducing a smart “phosphor pattern” design, free of causing inhomogeneous angular color distribution at the same time. The constructed LuAG:Ce PiGF‐based lighting source yields high brightness of 2970 lm@21 W mm −2 , and the constructed LuAG:Ce PiGF‐CASN:Eu PiGF‐based lighting source yields luminosity‐chromaticity balanced white light with LF higher than 1000 lm and color rendering index of 80–90.