Solid-state synthesis and luminescent properties of yellow-emitting phosphor NaY(MoO4)2:Dy3+ for white light-emitting diodes.

A yellow-emitting phosphor NaY(MoO4)2:Dy(3+) was synthesized using a solid-state reaction at 550 °C for 4 h, and its luminescent properties were investigated. Its phase formation was studied using X-ray powder diffraction analysis, and there were no crystalline phases other than NaY(MoO4)2. NaY(MoO4)2:Dy(3+) produced yellow emission under 386 or 453 nm excitation, and the prominent luminescence was yellow (575 nm) due to the (4) F9/2 → (6) H13/2 transition of Dy(3+). For the 575 nm emission, the excitation spectrum had one broad band and some narrow peaks; the peaks were located at 290, 351, 365, 386, 426, 453 and 474 nm. Emission intensities were influenced by the Dy(3+) doping content and a concentration quenching effect was observed; the phenomenon was also proved by the decay curves. Moreover, the Commission International de I'Eclairage chromaticity coordinates of NaY(MoO4)2:Dy(3+) showed similar values at different Dy(3+) concentrations, and were located in the yellow region.