Luminescence and photometric characterization of K+ compensated CaMoO4:Dy3+ nanophosphors.

A series of CaMoO4 phosphors doped with trivalent dysprosium (Dy(3+)) and codoped with potassium (K(+)) ions were prepared by hydrothermal method. The nanostructures of the as-synthesized phosphors were investigated by X-ray diffraction (XRD). The results reveal that the obtained powder phosphors are single-phase scheelite structure with tetragonal symmetry and the crystallite size is in the range of 10-60 nm. The emission spectra show a bright yellow emission at 576 nm and blue emission at 487 nm. As a charge compensator, K(+) ions were incorporated into CaMoO4:Dy(3+) phosphors, which enhance the PL intensities depending on the doping concentration of K(+). The CIE parameters such as colour coordinates, colour correlated temperature and luminous efficacy of radiation were calculated using spectral energy distribution functions and McCamy's empirical formula. Photometric characterization indicates the suitability of K(+) compensated CaMoO4:Dy(3+) phosphor for white LED applications.