Optical properties of lanthanide-doped lamellar nanohybrids

In this article a detailed study of the optical properties of lonthanide doped lamellar nanohybrids synthesized by the "benzyl alcohol route" is presented. The synthetic approach results in the formation of a highly ordered lamellar nanocomposite consisting of yttrium or gadolinium oxide crystalline layers with a confined thickness of about 0.6 nm, separated from each other by organic layers of intercalated benzoate molecules. When the inorganic layers are doped with optically-active lanthanide ions they show outstanding emission properties in the green (Tb3+), red (Eu3+) and near infrared (Nd3+). The local environment of the emitting ions and the energy transfer processes involving the phenyl ring of the benzoate complexes and the lanthanide ions ore presented, as well as radiance and lifetime measurements. The radiance values are comparable and in some cases even larger than those of standard phosphors, proving that these nanohybrids con compete, from an emission efficiency point of view, with commercial phosphors. Furthermore, in these nanohybrids it is possible by simply changing the excitation wavelength, to tune the emission colour chromaticity without loosing the radiance.