Strong red upconversion luminescence of NaYF4: Yb3+, Er3+ through Sc3+ ions doping for temperature sensing

The Sc3+ ions doped NaYF4: Yb3+, Er3+ upconversion (UC) nanoparticles are synthesized by thermal decomposition method. We successfully obtained the upconversion luminescence (UCL) nanoparticles from green emission to red emission through doping Sc3+ ions with different concentrations. Based on the XRD, the phase change process of Sc3+ ions doped NaYF4 nanocrystalline phase were demonstrated. More importantly, through the analysis of UC spectrum data, the change in the phase of the NaY/ScF4: Yb3+, Er3+ nanocrystalline corresponds to the change in its luminous properties. It determines that the change of crystal field will lead to the change of luminescence, and then modulate the luminescence. NaScF4: Yb3+, Er3+ UC nanoparticles exhibit strong red light emission. In addition, the temperature-sensitive properties of the optimal doping concentration of Sc3+ ion were tested. The sensitivity of NaYF4: Yb3+, Er3+ nanoparticles doped with Sc3+ ion reached the maximum value of 0.024 K- 1 at 498 K. The nanocrystalline has great application value in the fields of optical temperature measurement, biomedicine, bioprobes and colorful display.