Highly Optical Thermometry Based on Enhanced Up-Conversion Luminescence in Ba3yb4o9 : Er3+,M2+ (M

As significantly growing demand for noncontact temperature sensors, the exploitation of superior optical thermometers is increasingly pressing. Herein, Ba 3 Yb 4 O 9 :Er 3+ phosphors were successfully synthesized and the strategy of appropriate cation substitution (Mg 2+ , Ca 2+ , Sr 2+ ) is designed to strengthen the up-conversion luminescence as well as thermometric performance of Ba 3 Yb 4 O 9 :Er 3+ . Among them, Ba 3 Yb 4 O 9 :Er 3+ ,Mg2+ is identified to be an excellent optical thermometric material. Based on the fluorescent intensity ratio from thermal coupled energy levels ( 2 H 11/2 / 4 S 3/2 ) of Er 3+ , the relative (S R ) and absolute (S A ) sensitivities of Ba 3 Yb 4 O 9 :Er 3+ ,Mg 2+ can reach as high as 1.29% K -1 at 302 K and 0.43% K -1 at 573 K, respectively, which higher than that of Mg 2+ -free doped Ba 3 Yb 4 O 9 :Er 3+ (S R :1.15 %K -1 at 302 K; S A :0.38 %K -1 at 523 K). In addition, the sample exhibits outstanding reversibility and reproducibility. These results imply that Ba 3 Yb 4 O 9 :Er 3+ ,M 2+ (M=Mg, Sr, Ca) are superb candidates applied in temperature sensing fields