A multi-mode optical thermometer based on the up-conversion Ca3Y2Ge3O12: Er3+, Yb3+ phosphor

In order to develop a new up-conversion luminescent temperature measurement material with a garnet structure, Ca 3 Y 2 Ge 3 O 12 : Er 3+ , Yb 3+ phosphors were prepared by a simple high temperature solid phase method. The structural phase and luminescence characteristics of the samples were characterized by X-ray powder diffraction, field emission scanning electron microscopy and photoluminescence spectra. It can be observed that the characteristic emission of Er 3+ ion appears in the sample under 980 nm excitation, and it's up-conversion emission intensity increases with the increase of Yb 3+ ion concentration . The maximum relative sensitivity is 1.29 %K −1 , 1.09 %K −1 and 1.03 %K −1 based on the different temperature dependence of the thermal coupled energy levels (TCELs), non-thermal coupled energy levels (NTCELs) and the fluorescence lifetime (FL) of 4 S 3/2 state, respectively. The results show that Ca 3 Y 2 Ge 3 O 12 : Er 3+ , Yb 3+ phosphor is excellent a material for optical temperature measurement.