Near-infrared excitation and emitting thermometer based on Nd3+ doped ytterbium molybdate with thermally enhanced emissions

Lanthanides doped optical materials with temperature sensing property are of great interest for optical thermometry. However, most lanthanides doped luminescent materials for ratiometric thermometer are often accompanied by thermal quenching, which leads to a decrease in temperature sensing performance. Here, Nd3+ doped Yb2Mo3O12 phosphor with near-infrared upconversion emissions has been fabricated. A non-contact thermometer is constructed with the luminescence of Nd3+ ions and the change of the emission peak height ratio of 4F7/2-4I9/2 and 4F5/2-4I9/2 transitions. Interestingly, the intensity of the emission peaks in the prepared phosphor increases with increasing temperature. Avoiding thermal quenching, the thermally enhanced upconversion emission affords high sensing accuracy. The maximum relative and absolute sensitivity was 1.186% and 9.789 × 10−3 K−1, respectively. The results suggest that appropriate emission bands with thermal population are benefit for optical ratiometric thermometers.