Preparation and luminescent performances of thermally stable red-emitting phosphor-in-glass for high-power lighting

Phosphor-in-glass (PiG) has become as a promising resin-free color converter for high-power light-emitting diodes (LEDs). However, the challenge in luminescent performances of PiG still remain due to the deficiency of red emission spectrum. Herein, a stable red-emitting PiG was prepared for high-power lighting by introducing 3.5MgO·0.5MgF2·GeO2:Mn4+ (MFG:Mn4+) phosphor particles into a tellurite glass matrix. The microstructures and luminescent performances of prepared PiGs were investigated. PiG-based LEDs were fabricated by combining the prepared PiGs and ultraviolet (UV)-LED chips and their optical performances were adjusted by altering phosphor content. Consequently, the introduced phosphor crystals are chemically stable under sintering process and maintain intact in the glass matrix. With the increase of phosphor content, the red emission intensity is increased. Furthermore, the prepared PiG weakens the thermal quenching of MFG:Mn4+ phosphor and exhibits excellent thermal stability under high temperature operation. The results demonstrate that the prepared PiG is a stable and efficient red-emitting converter for high-power lighting.