Synthesis and luminescence properties of Eu3+ co-doped NaBi(MoO4)2:Dy3+ phosphors for white light-emitting diodes

Dy3+-doped and Dy3+/Eu3+ co-doped NaBi(MoO4)(2) phosphors were successfully synthesized using a high temperature solid-state method. The crystal structure and phase purity of these as-prepared samples were characterized by X-ray diffraction. Under 453nm excitation, NaBi(MoO4)(2):Dy3+ phosphors exhibited the characteristic weak blue emission peak at 488nm and strong yellow emission peak at 577nm, which originate from the (F9/2H15/2)-F-4-H-6 and (F9/2H13/2)-F-4-H-6 transitions of Dy3+ ions, respectively. Therefore, a white light could be composed of a blue light from chip and yellow emission of NaBi(MoO4)(2):Dy3+ phosphor. Additionally, color-tunable emissions were observed in the spectra of NaBi(MoO4)(2):Dy3+, Eu3+ phosphors due to efficient energy transfer from Dy3+ to Eu3+ ions. By varying co-doping concentrations of Dy3+ and Eu3+ ions, the emission color of NaBi(MoO4)(2):Dy3+, Eu3+ could be varied for high quality blue-excited white light-emitting diodes.