Non-contact thermometer behavior of (Y_0.5In_0.5)₂O₃:Yb³⁺,Er³⁺ solid solution

Oxides are physically and chemically stable. Non-contact thermometer-Yb³⁺-Er³⁺ ions co-doped solid solution (Y_0.5In_0.5)₂O₃, is prepared by the regular solid method. The structural results obtained by XRD indicate that a pure phase solid solution (Y_0.5In_0.5)₂O₃ has been obtained. The solid solution (Y_0.5In_0.5)₂O₃ has a similar crystal structure, especially Y₂O₃ and In₂O₃ with the same space group (Ia3̄). Green emission from 500 to 600 nm is due to Er³⁺ 4f-4f transitions: ⁴S_3/2 → ⁴I_15/2 at 567 nm and ²H_11/2 → ⁴I_15/2 at 528 nm. Red emissions from 630 to 720 nm are attributed to Er³⁺: ⁴F_9/2 → ⁴I_15/2. UC luminescence changes greatly with laser diode power and Er³⁺ and Yb³⁺ content. Furthermore, the two-photon process is confirmed to be dominant between Yb³⁺ and Er³⁺ in oxide solid solution (Y_0.5In_0.5)₂O₃. Optical temperature sensitivity is also investigated systematically in order to explore the application of the oxide solid solution (Y_0.5In_0.5)₂O₃. The temperature-dependent green fluorescence at 528 and 567 nm was investigated with the range of 313-573 K. 0.316% K^-1 is the maximum absolute sensitivity at 503 K, which is higher than most Yb³⁺/Er³⁺ co-doped systems. In addition, the solid solution (Y_0.5In_0.5)₂O₃:Yb³⁺,Er³⁺ has better thermal stability and stronger UC emission than a simple substance with excellent temperature sensing performance. It indicates that Yb³⁺-Er³⁺ ions co-doped (Y_0.5In_0.5)₂O₃ solid solution is a good candidate for optical temperature sensing.