The luminescence and temperature response characteristics of NaYF4 containing 15% NaYBF4 were investigated. NaYbF4@NaYF4 has good thermal stability and excellent response characteristics in the temperature in the range from 300 to 500 K, which significantly increases the upper limit of temperature detection of ytterbium temperature sensor. A self-calibration relationship between the reciprocal of temperature and the natural logarithm ratio of luminescent intensity has been discovered. Compared with the values of ln(I1048/I976) or ln (I947/I979) in Yb3+ emission spectra, the relationship between ln (I990/I967) and 1/T is not linear, but exponential attenuation relationship with better temperature resolution near 400 K. Oxygen has no influence on these relations because of the ordered and dense crystal structure, which leading to the separation of Yb3+ and oxygen.
