The invention discloses a red up-conversion
luminescent material, which belongs to the field of inorganic luminescent materials, the
chemical formula of the material is NaEr < 0.65 > F4: Yb < 0.2 > / Gd < 0.1 > / Tm < 0.05 >, and up-conversion microparticles of the red up-conversion
luminescent material are used as a
bifunctional luminescent temperature sensor which can be used for a 293348 K low-temperature region
sensitization sensor and a 348498 K high-temperature region
thermal quenching sensor. After near-
infrared light with the
wavelength of 980 nm excites Yb < 3 + > ions, through efficient
energy transfer between Er < 3 + > and Tm < 3 + >, different changes of near-
infrared response type 654 nm and 808 nm red up-conversion
luminescence characteristics can be used for non-contact optical
temperature measurement under the
extreme temperature condition. Temperature detection is realized based on
thermal coupling energy levels of 4F9 / 2 to 4I15 / 2 and 3H4 to 3H6, and the distance between two emission peaks is large, so that the
data processing error is greatly reduced; excitation light and emission light are located in an optical window of the
biological tissue, and absorption and self-
fluorescence of the
biological tissue are greatly reduced. The preparation method is based on the
green chemistry concept, takes water as a
solvent and adopts a one-step hydrothermal method for synthesis, the preparation method is simple, the required temperature is low, the preparation process is easy to control, the material
crystal phase is good, the phase is uniform, the yield is high, the material performance is stable, and the good
temperature response effect is achieved.