Abstract
Gd~4~Si~2~O~7~N~2~, a new oxynitride, has been prepared and the luminescent properties of the Ce^3+^, Tb^3+^ or Dy^3+^ doped product have been studied. XRD results indicate that Gd~4~Si~2~O~7~N~2~ is isostructural with Tb~4~Si~2~N~2~O~7~ and belongs to the monoclinic system. The SEM image shows that the synthesized powder disperses well and the particle diameter is between 1.40β4.0 ΞΌm. Upon excitation at 350 nm, Gd~4~Si~2~O~7~N~2~:Ce^3+^ 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 Ce^3+^ emission in Gd~4~Si~2~O~7~N~2~:Ce^3+^ is dipoleβdipole interactions. The emission colour of Gd~4~Si~2~O~7~N~2~:Tb^3+^ can be tuned from blue to green by changing the Tb^3+^ concentration. The ratio of yellow to blue emission for Gd~4~Si~2~O~7~N~2~:Dy^3+^ grows higher with an increase in the Dy^3+^ concentration. Energy transfer from the Gd^3+^ ions to Tb^3+^ or Dy^3+^ ions in the Gd~4~Si~2~O~7~N~2~ host was also observed.