Synthesis and luminescence properties of red-emitting phosphors NaY _(0.87)Eu_(0.13)(WO_4)_(1.2)(MoO _4)_(0.8)

摘要

A series of NaY_(1-y)Euy(WO_4) _(2-x)(MoO_4)_x (x=0-2 and y=0.06-0.15) phosphors have been prepared by a combustion route. X-ray powder diffraction, photoluminescence excitation and emission spectra were used to characterize the resulting samples. The excitation spectra of these phosphors show the strongest absorption at about 396 nm, which matches well with the commercially available n-UV-emitting GaN-based LED chip. Their emission spectra show an intense red emission at 616 nm due to the ~5D_0→~7F _2 electric dipole transition of Eu3. As the Mo content increases, the intensity of the ~5D_0→ ~7F_2 emission of Eu~3 activated at wavelength of 396 nm increases and reaches a maximum when the relative ratio of Mo/W is 2:3. The intense red-emission of the tungstomolybdate phosphors at near-UV excitation suggests that the material is a potential candidate for white light emitting diode (WLEDs).