Red and near-infrared emitting phosphors based on Eu- or Nd-doped lanthanum niobates prepared by the sol-gel route.

We have evaluated the structural and luminescence properties of Eu- or Nd-doped lanthanum niobate systems synthesized a sol-gel route and containing different dopant contents. XRD analysis revealed that the orthorhombic LaNbO and monoclinic LaNbO crystalline phases were present in all the samples, regardless of the dopant concentration. The excitation spectra of the samples displayed a broad band due to Nb→O charge transfer; this band was quite sensitive to the increasing Eu content.