Dual-mode Optical Thermometry with High Sensitivity Achieved in Na3Y(VO4)2:Yb3+/Er3+
Na3Y(VO4)2:Yb3+/Er3+upconversion(UC)material is synthesized by the high-temperature solid-state method,exhibiting strong luminescence in both green and NIR-Ⅱ region.In green region,optical thermometry based on the fluorescence intensity ratio(FIR)of Er3+:2H11/2→4I15/2 and 4S3/2→4I15/2 transition achieves optimal abso-lute sensitivity(SA),relative sensitivity(SR)and temperature resolution(δT)of 1.7%·K-1,1.2%·K-1 and 0.027 K,respectively.In NIR-Ⅱ region,optical thermometry based on the Stark splitting of Er3+:4I13/2→4I15/2 transition exhib-its optimal SA,SR and δT of 3.01%·K-1,0.59%·K-1 and 0.06 K,respectively.More importantly,both of the two optical thermometers show high accuracy for temperature measurement within the physiological temperature range.All data indicate that Na3Y(VO4)2:Yb3+/Er3+is an excellent luminescence material with the ability of high-sensitivity dual-mode optical thermometry in the visible and NIR region.
rare earth ionsupconversion luminescenceoptical thermometryfluorescence intensity ratio