Optical Temperature-Sensing Performance of La₂Ce₂O₇:Ho³⁺ Yb³⁺ Powders

In this paper, La₂Ce₂O₇ powders co-activated by Ho³⁺ and Yb³⁺ were synthesized by a high temperature solid-state reaction. Both Ho³⁺ and Yb³⁺ substitute the La³⁺ sites in the La₂Ce₂O₇ lattice, where the Ho³⁺ concentration is 0.5 at.% and the Yb³⁺ concentration varies in the range of 10~18% at.%. Pumped by a 980 nm laser, the up-conversion (UC) green emission peak at 547 nm and the red emission at 661 nm were detected. When the doping concentration of Ho³⁺ and Yb³⁺ are 0.5 at.% and 14% at.%, respectively, the UC emission reaches the strongest intensity. The temperature-sensing performance of La₂Ce₂O₇:Ho³⁺ with Yb³⁺ was studied in the temperature range of 303-483 K, where the highest relative sensitivity (S_r) is 0.0129 K^-1 at 483 K. The results show that the powder La₂Ce₂O₇:Ho³⁺, Yb³⁺ can be a potential candidate for remote temperature sensors.