Tunable Luminescence of Sm3+/Tb3+ Co-Doped CaMoO4 Phosphors Synthesized by Microwave-Assisted Heating

Abstract

We present a series of Sm3+/Tb3+ co-doped CaMoO4 phosphors synthesized by an efficient method of microwave-assisted heating. The prepared CaMoO4 samples were characterized by X-ray diffraction, photoluminescence, and Commission Internationale de l'Elcairage (CIE) chromaticity diagram. The X-ray diffraction results confirmed that all synthesized CaMoO4 samples are crystallized in a pure tetragonal phase. The photoluminescence spectra significantly show both red- and green emissions in the synthesized Sm3+/Tb3+ co-doped CaMoO4 phosphors. It is obvious that the variations in the intensity ratio of red/green emissions depend on the molar ratio of Sm3+/Tb3+ co-doping and dominate the CIE color coordinates on the chromaticity diagram. The investigations showed the functionality of the material system as advanced color-tunable phosphors for white-LEDs as evidenced by the controllability of the light-emitting region of Sm3+/Tb3+ co-doped CaMoO4 phosphors through the adjustment of the molar ratio of Sm3+/Tb3+ ions.