Synthesis and Luminescence Properties of a Red Nitride Phosphor (CaAlSiN3:Eu2+) for White Light LED Applications

Abstract

A combustion synthesis method has been developed for synthesis of Eu2+-doped CaAlSiN3 phosphor and its photoluminescence properties were investigated. Ca, Al, Si, and Eu2O3 powders were used as the Ca, Al, Si and Eu sources. NaN3 was added as both solid-state nitrogen source and reducing agent and NH4Cl was added as catalytic agent. These powders were mixed and pressed into a compact which was then wrapped up with an igniting agent (Mg+Fe3O4). The wrapped reactant compact was ignited by electrical heating under a N2 pressure of 0.2-1.0 MPa. Effects of experimental parameters on product yield and photoluminescence properties were investigated. The synthesized CaAlSiN3:Eu2+ phosphor absorbs light in the region of 200-600 nm and shows a broad band emission in the region of 500-800 nm due to the 4f65d1→4f7 transition of Eu2+. The peak emission intensity is ~106 % of a commercially available phosphor, YAG:Ce3+(P46-Y3), and the peak emission wavelength ranges from 610 to 680 nm depending on the Eu2+ concentration upon excitation at 460nm. The synthesized phosphor also shows excellent thermal and chemical stability and thus has a potential application as a red phosphor for white LED lighting.