Temperature sensing with Eu3+ doped TiO2 nanoparticles

Luminescence temperature sensing with Eu3+ doped TiO2 nanoparticles was tested over a temperature range of 307-533K. Anatase Eu3+:TiO2 nanoparticles of 10-20 nm in diameter are prepared using the hydrolytic sol-gel route. In photoluminescence emission spectra of Eu3+:TiO2 nanoparticles two distinct spectral regions are observed: the high energy spectral region associated with the trap emission of the TiO2 host, and the low energy spectral region with well resolved emission peaks of the Eu3+ ions. The ratio between Eu3+ emission and TiO2 trap emission, and the Eu3+ emission decay shows strong temperature dependence, and are tested for temperature sensing. It is found that relative sensor sensitivity ranges from 0.17 to 2.43%K-1 and is among the highest recorded for inorganic nanosensors. Temperature resolution is better than 1 K over a wide temperature range and reaches 0.33 K for decay measurements and 0.46K for the fluorescence intensity ratio measurements at about 400 K. (C) 2014 Elsevier B.V. All rights reserved.