Luminescence enhancement and tunable color emission in Eu/Dy/Sm codoped CaW1- xMoxO4 phosphor

A series of Eu3+- activated CaW1-xMoxO4 phosphors possessing schellite type crystalline structure were synthesized by using hydrothermal method to study the influence of molybdate doping on the luminescent performances of CaWO4:Eu3+ phosphors. The phase composition, vibrational spectra and luminescent properties were characterized by X-ray diffraction, fourier transform infrared, and photoluminescence spectroscopy. The addition of [MoO4] does not affect the crystalline phases of the synthesized materials. The effect of addition of [MoO4] into the (Ca,Eu)WO4 on the band gap of the phosphor and Eu3+ emission has been studied. The strongest emission at 618 nm is corresponding to 5D0→7F2 transition of Eu3+ under 273 nm excitation indicating that the site symmetry of the Eu3+ ions was not affected. A red shift in the excitation spectra of the [WO4] was observed with increasing [MoO4] content. Further, color-tunable emissions were also studied by the co-doping of Dy3+ and Sm3+ into the (Ca,Eu)W0.80Mo0.20O4 phosphor indicating the potential candidate for light emitting diodes.