Synthesis and optical properties of Dy3+, Li+ doped CaMoO4 phosphor

A series of CaMoO4 phosphors doped with trivalent dysprosium ions (Dy3+) and lithium (Li+) were prepared by solid state method at 750 degrees C for 3 h. X-ray diffraction (XRD) confirmed the crystal structure and quality of phosphors. Scanning electron microscopy (SEM) indicated that the phosphors presented good crystalline state, and the crystalline grain sizes were about 0.5-3.0 mu m. The emission spectra showed that the phosphors had intense emission at 480 (F-4(9/2)-> H-6(15/2)), 576 (F-4(9/2)-> H-6(13/2)) and 660 nm (F-4(9/2)-> H-6(11/2)). Meanwhile, the excited spectra indicated it had intense excitation at 352 (H-6(15/2)-> P-6(7/2)), 390 (H-6(15/2)-> M-4(21/2)) and 450 nm (H-6(15/2)-> I-4(15/2)). As a charge compensator, Li+ ions were incorporated into CaMoO4:Dy3+ phosphors, which enhanced the PL intensities depending on the doping concentration of Li+. The optimal molar fraction of Dy3+ ions in Ca1-xMoO4:xDy(3+), 0.05Li(+) was 0.05.