Fabrication of loss-less La3Si6N11:Ce3+ phosphor-in-glass color converters using oxygen-free ZIF-62 glass

Abstract

Ce³⁺-doped nitride phosphors are promising color converters in laser-driven lighting and display technologies, but they suffer from serious loss in luminescence efficiency caused by the interfacial reaction between phosphor powders and glass powders during the fabrication of phosphor-in-glass bulks or films. In this work, the oxygen-free organic–inorganic hybrid glass (OIHG) Zn(Im)₃(HbIm) (ZIF-62) was used instead of the traditional oxide glass to prepare an La₃Si₆N₁₁:Ce³⁺ (LSN) phosphor converter by cofiring LSN with the ZIF-62 glass. The LSN phosphor-in-ZIF-62 glass converter well maintains the internal quantum efficiency of the original phosphor powders, showing a luminescence loss of only ∼1%. The sandwich-structured LSN-in-ZIF-62 glass converter, constructed by cofiring it with sapphire substrates, enables the generation of white lighting with a maximum luminous flux of 872.2 lm and a luminous efficacy of 291 lm W⁻¹ when pumped by a blue laser diode at a powder density of 5.99 W mm⁻². The use of the oxygen-free ZIF-62 glass provides a viable method to design nitride phosphor-based color converters for low-power laser-driven lighting, high-power LED lighting or projection applications.