Up-conversion luminescence characteristics and temperature sensing of Y2O3: Ho3+/Yb3+ single crystal fiber

The Y2O3: Ho3+/Yb3+ single crystal fiber phosphor material has been prepared by laser heated pedestal growth (LHPG) method. The up-conversion (UC) luminescence emitted by the F-5(4)/S-5(2) -> I-5(8) and F-5(5) -> I-5(8) transitions of Ho3+ was obtained under a 976 nm laser. The UC luminescence features of the prepared phosphor material were studied and the fluorescence intensity ratio (FIR) of the green emission (F-5(4)/S-5(2) -> I-5(8)) to red emission (F-5(5) -> I-5(8)) of Ho3+ was analyzed over the range from 298 K to 623 K. The results show that the FIR of the two UC emissions of Ho3+ is sensitive to the change of temperature. However, the relation of FIR to temperature is not monotonous. Nevertheless, the FIR monotonously decreases with the increasing temperature in the range of 298-448 K, thus can be used for temperature sensing. At 298K, the absolute sensitivity and relative sensitivity reach 0.0489 K-1 and 0.0103 K-1, respectively, indicating that the Y2O3: Ho3+/Yb3+ single crystal fiber phosphor material can be a good candidate used for temperature sensor with high sensitivity.