Towards ultra-sensitive multimodal luminescent thermometers enabled by high crystal field strength of Lu2CaMg2Ge3O12:Yb3+,Nd3+,Er3+ phosphors
The exploration of acquiring excellent thermal performance of luminescence thermometers has become a key focus, owing to their non-contact measurement, high spatial resolution and rapid response. However, many luminescence thermometers still suffer from unsatisfactory relative sensitivity and a single temperature sensing mode. Herein, we report a Lu2CaMg2Ge3O12 garnet structure oxide with a stronger crystal field for ultra-sensitive and multimodal luminescence intensity ratio (LIR) optical thermometry based on the thermally coupled levels (TCLs) of Nd3+ (4F7/2 and 4F3/2) and Er3+ (2H11/2 and 4S3/2), where the relative sensitivity (Sr) can be up to 2.62% K−1 and 1.15% K−1, respectively. Furthermore, the energy level splitting factor Ke, which is used to quantify the energy level splitting extent of the doped ions, is estimated with the help of the dielectric chemical bond theory of complex crystals. As a result of the strong crystal field, the near-infrared (NIR) light-responsive temperature sensing performance of Er3+ (4I13/2) is enabled by the Stark sublevels with the relative sensitivity value of 0.46% K−1. This work not only provides a fresh perspective for developing optical thermometers with outstanding temperature performance, but also provides inspiration for pursuing a multimodal luminescence thermometer.
危险品化学品经营许可证（带存储）