Effect of Gd , Bi , or Sm on luminescent properties of La MgTiO :xEu phosphors.

Single phase of Bi , Gd , Sm and Eu co-doped La MgTiO 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 La MgTiO :xEu 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 Eu ion for La MgTiO is x = 0.5. The luminescent intensities of D  →  F transition of Eu in La MgTiO :0.5Eu , yBi /Gd /Sm were 1.31 times, 1.32 times and 1.88 times that of La MgTiO :0.5Eu at y = 0.08, 0.06, 0.06 for Bi , Gd , or Sm sensitizer, respectively. The chromaticity coordinates of La MgTiO :0.5Eu , 0.06Sm , (0.6342, 0.3513) were very close to those of the National Television Standard Committee (NTSC) standard red light coordinates.