Flexible and transparent films consisting of lanthanide complexes for ratiometric luminescence thermometry

Abstract Herein, a flexible and transparent film consisting Eu 3+ /Tb 3+ lanthanide complexes and poly(methylmethacrylate) was constructed via solution casting method, and further developed as a ratiometric luminescent thermometer with an excellent linear response to temperature variation from 77 to 297 K. The thermometer displays higher photo- and thermostability than corresponding pure complexs. Based on that the emission intensity ratio of 5 D 4  →  7 F 5 transition (Tb 3+ ) to 5 D 0  →  7 F 2 transition (Eu 3+ ) can be linearly related to the temperature, the resulting thermometer is not only more reliable than single Eu 3+ (or Tb 3+ ) material based on one emission, and but also has higher sensitivity than other types of luminescent thermometers. This work highlights the practical applications of luminescent films in temperature-sensing fields.