New Na5Y(MoO4)4: Yb3+, Er3+ phosphors: Up-conversion luminescence and temperature sensing characteristics

Abstract

Currently, the development of new up-converting fluorescent materials for manufacturing optical temperature sensing device with high accuracy and precision has always been significant pursuits of many researchers. In this work, we have synthesized new Na5Y(MoO4)4: Yb3+/Er3+ phosphors via solid-state reaction route, and the influences of dopant concentration on UCL performance were discussed. The results revealed that the introduction of Yb3+ enhanced the luminescence intensity, and the optimal concentration combination was 0.20Yb3+/0.04Er3+. Doping Yb3+ and Er3+ did not affect the phase structure of the phosphor. Several emission peaks at 529, 552 and 668 nm of Er3+ were found to be temperature-dependent within the scope of 298–573 K. Through the utilization of fluorescence intensity ratio technique (FIR, I529/I552 and I529/I668), dual-mode temperature measurement was realized. The maximum relative sensitivity (Sr-max) of 1.77 % K−1 (@298 K) utilizing thermally coupled energy levels (TCELs) and the maximum absolute sensitivity (Sa-max) of 12.0 % K−1 (@573 K) based on the non-TCELs were achieved. Furthermore, Yb3+/Er3+ co-doped Na5Y(MoO4)4 phosphors exhibited excellent photothermal repeatability and temperature resolution. The results indicated that the novel Na5Y(MoO4)4 phosphor provided the possibility for the development of temperature sensing materials with high sensitivity.