0D Cs<sub>3</sub>Cd<sub>1‐x</sub>Mn<sub>x</sub>Br<sub>5</sub> Nanocrystals Embedded in Glass for Optical Thermometry
Ying Ye, Kai Li, Luyue Niu, Jing Ren, Chao Liu
Abstract
Abstract Mn 2+ ‐activated metal halides are widely reported in multi‐functional optoelectronic applications. However, Mn 2+ ‐related optical thermometry is seldom discussed. In this work, all‐inorganic Cs 3 CdBr 5 nanocrystals (NCs) are precipitated in glass. Incorporation of Mn 2+ acts as a nucleation agent to promote the growth and improve the optical properties of Cs 3 CdBr 5 NCs embedded in glass with a photoluminescence quantum yield of 66%. It is found that [ MnBr 4 ]‐[ MnBr 4 ] structural units are strongly coupled in Cs 3 Cd 1‐x Mn x Br 5 NCs, leading to efficient energy transfer from a single [ MnBr 4 ] unit to [ MnBr 4 ]‐[ MnBr 4 ] couples and subsequent green‐red dual‐band emission with the same excitation spectra. The temperature‐dependence of green emission from the [ MnBr 4 ] unit and red emission from the [ MnBr 4 ]‐[ MnBr 4 ] couples results in high S a (0.0241 K −1 at 168 K) and S r (3.0346% K −1 at 74 K) from Cs 3 Cd 1‐x Mn x Br 5 NCs embedded in glasses. These results pave the way for novel Mn 2+ ‐activated metal halide NCs for high‐sensitive temperature sensors.