Internal Referencing Photoluminescence Probes for Simultaneous Sensing of O2 Gas and Temperature Based on Mn:MAPb(Br/Cl)3 Perovskite

Abstract

The ratiometric photoluminescence (PL)‐based O2 sensitive probes provide built‐in self‐calibration for the correction of various target‐independent influencing factors. They attract particular attention to be used for O2 gas sensing and imaging. Herein, internal referencing ratiometric PL probes are fabricated that not only detect O2 concentration and temperature simultaneously but also remove the destructive effect of temperature on O2 sensing. A dual‐emission thin film of Mn‐doped halide perovskite nanocrystals (PNCs) (Mn:MAPb(Br/Cl)3) with a 50% PL quantum yield is used as the sensing layer, which is synthesized in situ. Through the sensing process, excitonic PL and the PL caused by Mn are used for detecting temperature and O2 partial pressures, respectively. Remarkably, the Mn PL intensity shows 40% decrement with increasing O2 partial pressures from 0% to 20%, while for the excitonic PL, intensity changes are less than 5%. As the temperature undesirably affects the sensing quantity, the O2 PL is used as an internal reference signal to achieve good accuracy and selectivity. Furthermore, the temperature variation is determined by measuring PL peak intensity change and wavelength shift. In addition to the O2 gas sensitivity of 1.55, a relative temperature sensitivity of −9.36% K−1 is also achieved.