Co-doped Y₂O₃:Tb³⁺/Tm³⁺ multicolor emitting phosphors for thermometry

In this study, the new temperature-dependent phosphor, Y₂O ₃:Tb³⁺=Tm³⁺, was investigated for high-temperature thermometry. The photoluminescence intensity at 456nm emitted from Tm³⁺ was strong at temperatures higher than 1100K, whereas the peak intensities emitted from Tb³⁺ decreased due to the thermal quenching effect. Thus, the intensity ratio between those emissions showed an appropriate variation for thermometry over a wide temperature range. In addition, the phosphors showed a distinct change of visible emission colors from green to blue with increasing temperature. These findings suggest the applicability of these phosphors in visual thermo-sensors.