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

Developing a contactless ratiometric luminescent thermometry with high sensitivity, widely available temper-ature 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 reac-tion 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.

Automated summary

In this study, luminescent lanthanide complexes were synthesized in a siloxane-polyether matrix using an in-situ formation strategy, achieving ratiometric luminescent thermometry. The siloxane-polyether matrix allows for multi-color emission and high sensitivity over a wide temperature range.