Novel high-efficiency up-conversion luminescence of Er3+ doped LiYbW2O8 phosphors for optical temperature sensing investigation

A novel series of Er 3+ doped LiYbW 2 O 8 phosphors were synthesized by high-temperature solid-state process. Upon 980 nm NIR laser excitation , the up-conversion emission spectra show that the intense green emissions and weak red emissions can be proposed as the transitions of 2 H 11/2 → 4 I 15/2 , 4 S 3/2 → 4 I 15/2 , 4 F 9/2(2) → 4 I 15/2 and 4 F 9/2(1) → 4 I 15/2 of Er 3+ ions, respectively. The optical temperature sensing properties were carefully investigated on the basis of fluorescence intensity ratio (FIR) technology about energy level transitions of 2 H 11/2 → 4 I 15/2 and 4 S 3/2 → 4 I 15/2 in the range from 300 K to 500 K. Moreover, the maximum values of relative sensitivity ( S r ) and absolute sensitivity ( S a ) are separately about 1.62% K −1 at 300 K and 0.64% K −1 at 500 K, which can prove that the sensitivity of LiYbW 2 O 8 :Er 3+ is superior to the latest reported materials for temperature sensors . Results evidence that the Er 3+ doped LiYbW 2 O 8 phosphors can be outstanding candidates for optical temperature sensors with high S r and S a .