Er3+-sensitized upconversion emission of Tm3+via Yb3+-mediated energy migration for nanothermometry

Abstract

The dedicated control of lanthanide-mediated energy migration within a nanostructure can help realize plenty of intriguing luminescence behaviors. In this work, an Er³⁺-sensitized upconversion emission of Tm³⁺ by means of Yb³⁺-mediated energy migration has been firstly realized with a core/shell nanostructure. The analysis of the luminescence thermal behavior of the nanostructure indicates that the heating-induced alleviation of energy migration-mediated surface quenching leads to the thermal enhancement of Tm³⁺ emission, while the green emissions of Er³⁺ exhibit thermal quenching. By leveraging the thermal quenching, heating-induced alleviation of surface quenching and the characteristic of thermally coupled levels, specifically, a ratiometric luminescent nanothermometer has been developed via the combination of emissions from both Tm³⁺ and Er³⁺, which exhibits a high relative sensitivity up to 3.46% K⁻¹. This work may offer a promising design route toward luminescent nanothermometers.