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

Abstract

A novel series of Er3+ doped LiYbW2O8 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 2H11/2→4I15/2, 4S3/2→4I15/2, 4F9/2(2)→4I15/2 and 4F9/2(1)→4I15/2 of Er3+ ions, respectively. The optical temperature sensing properties were carefully investigated on the basis of fluorescence intensity ratio (FIR) technology about energy level transitions of 2H11/2→4I15/2 and 4S3/2→4I15/2 in the range from 300 K to 500 K. Moreover, the maximum values of relative sensitivity (Sr) and absolute sensitivity (Sa) 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 LiYbW2O8:Er3+ is superior to the latest reported materials for temperature sensors. Results evidence that the Er3+ doped LiYbW2O8 phosphors can be outstanding candidates for optical temperature sensors with high Sr and Sa.