Eu3+/Tb3+ bimetallic complex-doped siloxane-polyether hybrid film for luminescent thermometry

Abstract

Developing a contactless ratiometric luminescent thermometry with high sensitivity, widely available temperature range, and reliable performance is still a challenge in materials science. Herein, we adopted an in-situ formation strategy to synthesize luminescent lanthanide complexes in siloxane-polyether matrix by the reaction between 4′-(4-carboxyphenyl)- 2,2′:6′,2″- terpyridine (Hcptpy) ligand and lanthanide ions (Eu3+/Tb3+) to realize a ratiometric luminescent thermometer. The unique energy cascade from Hcptpy → Tb3+ → Eu3+ in siloxane-polyether enables the luminescent films to be not only the multi-color emission, but also provide highly temperature-sensitive over the wide temperature range. The EuTb15@SP film for luminescent thermometry performance is fine-tuned to reach a maximum relative sensitivity of 7.26% K−1 at 397 K and shows repeated utilization without sensitivity loss. Furthermore, the multi-color emission ranging from red through yellow to green can be achieved by tuning the Eu3+/Tb3+ molar ratio. Consequently, utilizing siloxane-polyether as matrix has been proven to be an effective strategy for constructing lanthanide-based hybrid films with temperature sensor properties. We believe that the reported strategies for preparing a bimetallic complex-doped siloxane-polyether hybrid film will broaden potential applications.