Green up-conversion luminescence and optical thermometry of Yb3+/Er3+ co-doped LiLuW2O8 phosphor

Up-conversion fluorescent materials serve a significant function as the detection materials of temperature sensors . In this study, a series of green-emitting LiLuW 2 O 8 :Yb 3+ , Er 3+ phosphors applied in optical temperature sensing detection were successfully synthesized via the solid-state process in air. The crystal structure, luminescence properties, luminescence mechanism, and optical temperature sensing properties of samples were investigated. LiLuW 2 O 8 :Yb 3+ , Er 3+ phosphor with excitation at 980 nm emits pronounced green emissions owing to the 2 H 11/2  →  4 I 15/2 and 4 S 3/2  →  4 I 15/2 transitions of Er 3+ ions. The whole emission processes of LiLu 0.72 W 2 O 8 :0.24 Yb 3+ , 0.04Er 3+ sample are all two-photon processes. Moreover, we apply thermal coupling levels ( 2 H 11/2 , 4 S 3/2 ) for temperature sensing and the value of sensing sensitivity can reach the maximum of about 1.41% K −1 . All the experimental results imply that LiLuW 2 O 8 :Yb 3+ , Er 3+ phosphors show good potential in temperature sensing.