Perovskite nanocrystals@covalent organic framework as a nanothermometer for sensitive temperature sensing

Abstract

Perovskite nanocrystal-based temperature sensors have drawn extensive attention. Improving the photostability of perovskites and their sensitivity to temperature are urgent issues that need to be addressed. Herein, a nanothermometer for color-changing temperature indicators is designed based on perovskite nanocrystals encapsulated in a covalent organic framework (CsPbBr₃ NCs@COF–V). Different temperature-response fluorescence behaviors originate from the photoluminescence of CsPbBr₃ NCs at 522 nm. CsPbBr₃ NCs@COF–V achieves temperature sensing in the range of 20–89 °C and shows high potential as a thermometer for monitoring the body temperature. Significantly, spherical COF–V boosts fluorescence stability, fluorescence lifetime, and sensitivity to temperature of CsPbBr₃ NCs.