The photoluminescence (PL) properties of post-treated Pr3+-doped (K0.5Na0.5)NbO3 (KNN:Pr3+) have been investigated for oxygen sensing. It is found that both the intensity ratio of the 1D2-3H4 red emission to the 3P0-3H4 blue-green emission and their absolute intensity have a strong response to oxygen adsorption at room temperature and elevated temperature. Especially, at 165 °C, the 1D2-3H4 emission intensity measured in a 100% O2 atmosphere was ∼3 folds higher than that in 100% N2, which is the highest response in all PL-based gas sensing oxides reported so far. Moreover, the high oxygen-sensing recoverability and reproducibility have been demonstrated. It is proposed that the intervalence charge transfer mechanism plays a key role in sensing. Together with the inherent ferroelectric and PL properties of KNN:Pr3+, the product may hold considerable potential in multifunctional devices.
All Science Journal Classification (ASJC) codes
- Materials Chemistry