MnII-Doped Cesium Lead Chloride Perovskite Nanocrystals: Demonstration of Oxygen Sensing Capability Based on Luminescent Dopants and Host-Dopant Energy Transfer

The design of photoluminescence-quenching probes for molecular oxygen (O 2 ) is always a large space to explore. Luminescent semiconductor nanocrystals (NCs) have been proposed as emerging oxygen-responsive probes, but the inherent O 2 sensing of phosphorescent semiconductor NCs has not been reported so far. Here, we demonstrate the O 2 sensing capability of Mn II -doped CsPbCl 3 nanocrystals (Mn:CsPbCl 3 NCs) and reveal the role of O 2 on the optical de-excitation process of such perovskite nanocrystals (PNCs). By adjusting the amount and distribution of Mn II dopants, as well as the host-dopant energy transfer process in PNCs, we highlight that O 2 can reversibly quench the Mn II emission due to the temporary disturbance to the ligand field of near-surface Mn II dopants in PNCs. In phosphorescence mode, the photoluminescence intensity of the Mn:CsPbCl 3 NCs is quenched by 53% on increasing O 2 concentration from 0 to 100%. The Stern–Volmer plot shows a good linear in the 0–12% O 2 concentration range. High sensing reversibility and rapid signal response are also achieved. In our perception, the mechanism study makes our PNCs candidates for the optical probes of O 2, and it is enlightening to explore more possibilities of the inherent O 2 sensing based on the semiconductor-doped NCs (not restricted to Mn II -doped PNCs) with phosphorescence emission.