Photoluminescence properties of NaGd(WO4)2:Eu3+ nanocrystalline prepared by hydrothermal method

NaGd(WO4)2:Eu3+ (hereafter NGW:Eu) red-phosphors were synthesized via a facile hydrothermal method at different pH value. X-ray power diffraction (XRD), transmission electron microscope (TEM), energy dispersive X-ray spectra (EDS), photoluminescence excitation and emission spectra and decay curve were used to characterize the NGW:Eu phosphors. It was found that the pH value has a crucial effect on synthesis of the scheelite structure NGW:Eu. The intense red emission is obtained by exciting into the 5L6 state with 395 nm, which corresponds to the popular emission line from near-UV LED chips. The values of Ω2,4 experimental intensity parameters (14.9 × 10−20 and 5.6 × 10−20 cm2) are determined. The high emission quantum efficiency and suitable color coordination of the NGW:Eu phosphor suggest the material could be a promising red phosphor for generating white light in phosphor-converted white light emitting diodes (WLEDs).