Inorganic phosphors in lead–silicate glass for white LEDs

Abstract

Luminescent composites of the “phosphor-in-glass” type, based on a highly reflective lead–silicate matrix and fine-grained powders of YAG:Ce³⁺ and SiAlON:Eu²⁺ crystals, are developed and synthesized. Phosphor and glass powders are sintered at a temperature of 550°C to obtain phosphor samples for white LEDs. The composites are analyzed by X-ray diffraction and luminescence spectroscopy. The dependence of the light quantum yield on the SiAlON:Eu²⁺ content in the samples is investigated. A breadboard of a white LED is designed using a phosphor-in-glass composite based on lead–silicate glass with a low glasstransition temperature. The total emission spectra of a blue LED and glass-based composites are measured. The possibility of generating warm white light by choosing an appropriate composition is demonstrated.