Effect of Gd3+ , Bi3+ , or Sm3+ on luminescent properties of La2-x MgTiO6 :xEu3+ phosphors.

Single phase of Bi3+ , Gd3+ , Sm3+ and Eu3+ co-doped La2 MgTiO6 red phosphors were synthesized by high temperature solid-state method. The phase composition, morphology and fluorescent properties of the phosphors were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectrometer. The La2-x MgTiO6 :xEu3+ phosphors can be excited by UV (396 nm) and blue (465 nm) light-emitting diode (LED) chips and show a strong red emitting with dominated wavelength at 615 nm. The optimum doping concentration of Eu3+ ion for La2 MgTiO6 is x = 0.5. The luminescent intensities of 5 D0  → 7 F2 transition of Eu3+ in La1.5-y MgTiO6 :0.5Eu3+ , yBi3+ /Gd3+ /Sm3+ were 1.31 times, 1.32 times and 1.88 times that of La1.5 MgTiO6 :0.5Eu3+ at y = 0.08, 0.06, 0.06 for Bi3+ , Gd3+ , or Sm3+ sensitizer, respectively. The chromaticity coordinates of La1.44 MgTiO6 :0.5Eu3+ , 0.06Sm3+ , (0.6342, 0.3513) were very close to those of the National Television Standard Committee (NTSC) standard red light coordinates.