Developing Smart Temperature Sensing Window Based on Highly Transparent Rare-Earth Doped Yttrium Zirconate Ceramics

Lanthanide-ion-based thermometers have been widely researched and utilized as contactless temperature sensing materials. Cooperating with the unique optical and excellent physical properties of transparent ceramics, Er³⁺/Yb³⁺ co-doped Y₂Zr₂O₇ transparent ceramics were successfully fabricated as temperature sensing window materials. Homogeneous distribution of elements inside samples together with high transmittance (nearly 73%) makes it possible as an observing window. Upon excitation at 980 nm, room-temperature luminescent performance was systemically researched for explaining the energy transfer mechanism between Yb³⁺ and Er³⁺ ions. The FIR method was introduced for thermally coupled energy levels to realize temperature sensing ability. Detecting sensitivity at different temperatures was also calculated (1.24% K^-1 at 303 K), suggesting that Yb³⁺, Er³⁺:Y₂Zr₂O₇ are adequate for high sensitivity temperature detecting application. It is also investigated that the concentration of Yb³⁺ ions not only affects the emission color at room-temperature but also has influence on the sensitivity of temperature and 10 mol % Yb³⁺, 2 mol % Er³⁺:Y₂Zr₂O₇ was found to be the most sensitive one. A demonstration experiment was also carried out to validate its application as a smart temperature sensing window. These results suggested that Yb³⁺, Er³⁺:Y₂Zr₂O₇ transparent ceramics can have potential for temperature monitoring applications, especially as novel window materials under extreme circumstances.