Wide-range temperature sensing of NaYF4: Ho3+ nanoparticles by multi-emissions in dual spectral ranges

NaYF4: Ho3+ nanoparticles (NPs) were synthesized by co-precipitation method. The temperature-dependent emission spectra were measured from 113 K to 473 K under the excitation of 447 nm. Fluorescence intensity ratios (FIRs) of multi-emissions in both visible and near-infrared ranges are used for investigating the temperature sensing performance of these NPs. High relative temperature sensitivities (>0.7%∙K−1) can be achieved in the range of 236 K–415 K and 308 K–450 K for the FIRs of 542nm645nm (visible) and 1183nm961nm (NIR), respectively. These results show that NaYF4: Ho3+ NPs present good temperature sensing performance in both visible and near-infrared range, which would broaden application prospects of nanoscale non-contact temperature sensing.