Judd-Ofelt Analysis of Eu3+ Emission in TiO2 Anatase Nanoparticles

Abstract

Preparation and spectroscopic studies of the TiO2 nanopowders doped with Eu3+ ions are described. Efficient emission in the red part of the visible spectrum can be obtained due to the D-5(0) - GT F-7(2) emission of europium ions. Quantum efficiency of such emission was estimated to be about 0.83, which indicates a rather weak role of the non-radiative losses. However, the increase of Eu3+ concentration up to 10 at% significantly lowers the quantum efficiency because of the energy transfer and re-absorption processes. Higher doping concentrations (larger than 3 at% of Eu3+) also decrease the covalency of the Eu3+-O2- chemical bonds.