Synthesis and photoluminescence properties of Ca9Y(VO4)7:Dy phosphors for white light-emitting diodes

Ca9Y(VO4)7:Dy3+ phosphors were successfully synthesized by the solid-state reaction. X-ray diffraction, photoluminescence excitation and emission spectra were used to characterize the resulting samples. The phosphors under the excitation of charge transfer band exhibit blue emission (480 nm) and strong yellow emission (571 nm), corresponding to the 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions of Dy3+ ions, respectively. The cross relaxation processes and the exchange interaction between Dy3+ ions are identified as the mechanisms for the concentration quenching. The color coordinate analysis indicates that Ca9Y(VO4)7:Dy3+ phosphors may have potential applications for white light emitting diodes.