Preparation and luminescence characterization of Zn(1−x)MoO4: xDy3+ phosphor for white light-emitting diodes

Different concentrations of Dy3+ ions activated ZnMoO4 luminescent phosphors were prepared using the solid-state reaction method by sintering at 900 °C. Phase purity features of the prepared phosphors were characterized by X-ray diffraction (XRD) patterns and the particle size has been found to be about 40 nm. The compositional and structural details were carried out using Fourier transform infrared (FTIR) spectrum. The characteristic emission peaks of Dy3+ ions were observed due to the 4F9/2→6H15/2 (490 nm) and 4F9/2→6H13/2 (580 nm) transitions. The variation of luminescence intensity with Dy3+ ions concentrations as well as with different excitation wavelengths has been discussed. The CIE chromaticity color coordinates (x, y) were calculated from the luminescent characteristics of ZnMoO4: Dy3+ phosphors, which fall in the white light region of the chromaticity diagram. The lifetime of 4F9/2 excited level has been quenched due to the energy transfer among Dy3+ ions at higher concentrations.