A highly sensitive upconverting nano-glass-ceramic-based optical thermometer.

Yb/Tm: YF 3 nanoparticles embedded transparent bulk glass ceramic was successfully prepared to explore its possible application in optical temperature sensors. Specifically, owing to the competition of electron population in the thermally coupled Tm 3+ 3 F 2,3 and 3 H 4 excited states, two upconversion emission bands corresponding to Tm 3+ : 3 F 2,3 → 3 H 6 transition and 1 G 4 → 3 F 4 one exhibited opposite temperature-dependent behaviors, which resulted in monotonous enhancement of the related fluorescence intensity ratio with increase of temperature. As a consequence, Tm 3+ activators in the present YF 3 glass ceramic had advantages of a high sensitivity of 1.84% per K, an avoidable spectral overlapping and a negligible thermal effect for accurate temperature detecting. [ABSTRACT FROM AUTHOR]