0D Cs3Cd1‐xMnxBr5 Nanocrystals Embedded in Glass for Optical Thermometry

Abstract

AbstractMn2+‐activated metal halides are widely reported in multi‐functional optoelectronic applications. However, Mn2+‐related optical thermometry is seldom discussed. In this work, all‐inorganic Cs3CdBr5 nanocrystals (NCs) are precipitated in glass. Incorporation of Mn2+ acts as a nucleation agent to promote the growth and improve the optical properties of Cs3CdBr5 NCs embedded in glass with a photoluminescence quantum yield of 66%. It is found that [MnBr4]‐[MnBr4] structural units are strongly coupled in Cs3Cd1‐xMnxBr5 NCs, leading to efficient energy transfer from a single [MnBr4] unit to [MnBr4]‐[MnBr4] couples and subsequent green‐red dual‐band emission with the same excitation spectra. The temperature‐dependence of green emission from the [MnBr4] unit and red emission from the [MnBr4]‐[MnBr4] couples results in high Sa (0.0241 K−1 at 168 K) and Sr (3.0346% K−1 at 74 K) from Cs3Cd1‐xMnxBr5 NCs embedded in glasses. These results pave the way for novel Mn2+‐activated metal halide NCs for high‐sensitive temperature sensors.