Luminescence properties of Gd₂MoO₆:Eu³⁺ nanophosphors for WLEDs

A series of Gd_2-xMoO₆:xEu³⁺ (x = 0.18-0.38) nanophosphors were synthesized by the solvothermal method. The properties of these nanophosphors were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), fluorescence spectroscopy and diffuse reflectance spectroscopy. Gd_2-xMoO₆:xEu³⁺ nanophosphors have a strong excitation band in the NUV region and emit red light with high color purity by efficient energy transfer from the MoO₆^6- group to Eu³⁺ ions. Red LEDs and WLEDs were fabricated using a 370 nm chip and Gd_2-xMoO₆:0.26Eu³⁺ nanophosphors, which showed good electroluminescence performance. At a driving current of 20 mA, WLEDs displayed CIE coordinates of (0.3297, 0.3869), a correlated color temperature (CCT) of 5604 K and a high color rendering index (R_a) of 91.6. This work demonstrates that Gd_2-xMoO₆:xEu³⁺ phosphors are promising red phosphors excited by a NUV chip for WLEDs.