A high sensitivity dual-mode optical thermometry based on charge compensation in ZnTiO3:M (M = Eu3+, Mn4+) hexagonal prisms

Abstract

Optical thermometer based on dual-mode fluorescence intensity ratiometric thermometry has been attracted more attention due to its higher sensitivity. In order to obtain optical thermal probe with high sensitivity, ZnTiO3 hexagonal prisms with hexagonal perovskite structure were fabricated by using self-assembly method, and Al3+ ions were introduced into the crystal lattices of ZnTiO3 doped with Eu3+/Mn4+ to improve the optical properties. The emission intensity assigned to Eu3+ was enhanced about twice with the charge compensation of Al3+ between Eu3+ and Ti3+. While the luminescence ratio between the thermal coupled level of Eu3+ revealed poor temperature dependence property. The emission assigned to 2Eg→4A2g (713 nm) transition of Mn4+ revealed an huge thermal quenching. Using the luminescence ratio between 5D0→7F2 (5D0→7F1) transition of Eu3+ to 2Eg→4A2g of Mn4+, the higher relative sensitivity of 2.7 %K-1was obtained. The charge compensation of Al3+ improved the coordination and reduced the relative sensitivity, Sr =1.85 %K−1. The results suggested the potential application in optical temperature probes for ZnTiO3: Mn4+,Eu3+ phosphor.