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 LiLuW2O8:Yb3+, Er3+ 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. LiLuW2O8:Yb3+, Er3+ phosphor with excitation at 980 nm emits pronounced green emissions owing to the 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 transitions of Er3+ ions. The whole emission processes of LiLu0.72W2O8:0.24 Yb3+, 0.04Er3+ sample are all two-photon processes. Moreover, we apply thermal coupling levels (2H11/2, 4S3/2) 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 LiLuW2O8:Yb3+, Er3+ phosphors show good potential in temperature sensing.