Synthesis and Luminescent Properties of Cerium-, Terbium-, or Dysprosium-Doped Gd4Si2O7N2 Materials

Gd4Si2O7N2, a new oxynitride, has been prepared and the luminescent properties of the Ce3+, Tb3+ or Dy3+ doped product have been studied. XRD results indicate that Gd4Si2O7N2 is isostructural with Tb4Si2N2O7 and belongs to the monoclinic system. The SEM image shows that the synthesized powder disperses well and the particle diameter is between 1.40- 4.0 mu m. Upon excitation at 350 nm, Gd4Si2O7N2:Ce3+ exhibits blue emission peaking at 445 nm, which may have potential application as a blue phosphor in the field of solid state lighting. The major mechanism for the concentration quenching of the Ce3+ emission in Gd4Si2O7N2:Ce3+ is dipole-dipole interactions. The emission colour of Gd4Si2O7N2:Tb3+ can be tuned from blue to green by changing the Tb3+ concentration. The ratio of yellow to blue emission for Gd4Si2O7N2:Dy3+ grows higher with an increase in the Dy3+ concentration. Energy transfer from the Gd3+ ions to Tb3+ or Dy3+ ions in the Gd4Si2O7N2 host was also observed.