A robust red-emitting phosphor-in-glass (PiG) for use in white lighting sources pumped by blue laser diodes
A red-emitting phosphor-in-glass (PiG) material was synthesized by dispersing CaAlSiN3:Eu2+ phosphor powders in a ZnO-B2O3-BaO-Al2O3 glass matrix. A fully densified translucent CaAlSiN3:Eu2+ PiG material was achieved at 650 °C for 40 min with an external quantum efficiency (QE) of 43%, transmittance of 30% at 640 nm and thermal conductivity of 1.12 Wm−1K−1. The CaAlSiN3:Eu2+ particles were distributed in the glass matrix uniformly, and no serious interfacial reactions occurred between the glass matrix and the contained phosphor particles. Under the excitation of blue laser, the maximum luminous flux of CaAlSiN3:Eu2+ PiG sample is 39 lm at the laser flux density of 0.5 W/mm2. Although luminous saturation was observed at high laser incident density, the PiG material would be a promising red color converter for use in white lighting sources pumped by blue laser diodes.