High-Sensitivity Optoelectronic Temperature Sensing Using Rare Earth Luminescent Materials for Antenna Radome Temperature Monitoring

In this study, a multilayer composite material, TiO₂@Y₂Ti₂O₇@YOF:Yb,Tm (TYY), was designed based on the highly polar O-metal bond for high-sensitivity optical temperature sensing. By introducing highly electronegative oxygen atoms to form strong crystal field interactions with Ti⁴⁺, the coupling between rare-earth ions and high-energy phonons was enhanced, thereby increasing the probability of nonradiative transitions. Leveraging the significant thermal quenching effect of the 480 nm emission peak and the stable temperature response of the 1610 nm emission peak, a near-infrared II/visible ratio-metric fluorescence temperature sensor was successfully constructed, achieving an ultrahigh sensitivity of 5.8%·K^-1 at 303 K. To further reduce sensor complexity and cost, a single-peak fluorescence intensity-based temperature sensor using the integrated intensity of the 480 nm emission was developed, achieving a high sensitivity of 2.2%·K^-1 at 413 K. X-ray diffraction (XRD) analysis revealed that differences in thermal expansion coefficients between the shell layers induced lattice distortion in the YOF layer, further enhancing nonradiative transitions and improving temperature sensing sensitivity. Finally, the internal temperature detection of the antenna radome using TYY as a single-peak sensor was achieved through a mobile imaging device. A good linear relationship between fluorescence intensity and temperature was observed, highlighting the broad application potential of TYY in industrial temperature monitoring.