Patterned glass ceramic design for high-brightness high-color-quality laser-driven lightings

Abstract

Up-to-date laser-driven lightings confront a challenge of simultaneously achieving good photometric and chromatic performances. Herein, the coupling of “patterned package design” and “phosphor wheel” was proposed and demonstrated effectively to deal with this tough issue, based on a new architecture of CaAlSiN3:Eu2+ (CASN:Eu) glass ceramic film (GCF) on Y3Al5O12:Ce3+ (YAG:Ce) GC plate. The fabricated composite has no interface between the two functional layers and retains the admirable luminescent features from CASN:Eu and YAG:Ce for the microstructural integrity during co-sintering. The studies on laser-microcrystalline interactions reveal that the luminescence saturation is almost determined by thermal quenching for YAG:Ce, but is ascribed to thermal/intensity quenching which are equally crucial for CASN:Eu. Benefiting from the elaborate architecture design, good color chromaticity tunability was obtained, and severe photon reabsorption was reduced. Moreover, accompanied with the rotation induced increase of thermal convection to air and pulse-like excitation, the constructed lighting engine under blue laser driven shows bright white light with luminous flux (LF) higher than 1000 lm, adjustable chromaticity from cool to warm, and improved color rendering index (CRI) approaching to 70.