Nanocrystalline TiO2 films doped by Eu were obtained by low-pressure hot target reactive sputtering at different annealing temperatures and then characterized both structurally and optically. Strong emission assigned to europium ions was observed in the visible range. No emission related to the TiO2 Matrix was detected, indicating all efficient excitation transfer from the matrix to the ions under nonresonant excitation. Europium emission strongly depends on the annealing temperature and reaches a maximum intensity for the sample annealed at 670 K before dropping sharply ill higher temperatures. Emission, absorption. and photoluminescence excitation measurements Indicate that this effect results from the influence of defect formation at higher temperatures. (c) 2009 The Electrochemical Society. [DOI: 10.1149/1.3056039] All rights reserved.