Synthesis and luminescence properties of a novel Na6CaP2O9:Sm3+ phosphor

Trivalent samarium doped red phosphors Na6CaP2O9 were prepared for the first time via high temperature solid state reaction method at 1000 °C. The obtained powders were structurally characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) analyses. The thermal and photo-luminescent properties were also investigated. The calculated Commission International de lʹEclairage (CIE) chromaticity coordinates of the Sm3+ ions doped Na6CaP2O9 lie in the region of white light. The host matrix has shown a strong blue emission when excited with 403 nm, which has its maximum intensity centered at 475 nm. Red fluorescence originating from intra 4 f 4G5/2→6H7/2 transition of Sm3+ is observed by introducing Sm3+ ions into the host lattices of Na6CaP2O9 phosphors. The possible energy transfer mechanism from the host to Sm3+ ions are analyzed by diffuse reflectance spectroscopy (DRS) analysis. These results suggesting that the Na6CaP2O9:Sm3+ phosphors may be a promising blue/red component for cost-effective near UV white light emitting diodes (NUV W-LEDs).