Synthesis and optical temperature sensing performance of NaLa(MoO4)2: Tb3+, Eu3+ phosphors

Abstract

Abstract NaLa(MoO 4 ) 2 : Tb 3+ , Eu 3+ phosphors were prepared via the hydrothermal method using sodium citrate as chelating agent, and different morphologies of the samples were obtained through the change of the Na 3 Cit molar ratio to rare earth ions. The NaLa(MoO 4 ) 2 : Tb 3+ , Eu 3+ phosphors' structure, morphology, and temperature sensing performance were investigated using XRD (X-ray diffraction) and FE-SEM (Field Emission Scanning Electron Microscope) as well as temperature-dependent emission spectra. The XRD demonstrated that all the materials are body-centered tetragonal phase. The FE-SEM results show that a dosage of sodium citrate could control the NaLa(MoO 4 ) 2 : Tb 3+ , Eu 3+ phosphors' morphology. On the basis of the temperature-dependent emission spectra, the FIR (Fluorescence Intensity Ratio) of Eu 3+ and Tb 3+ in all the samples changed with the temperature and could represent the temperature. Furthermore, the phosphors' sensitivity increased with the value of Cit 3− /Re 3+ . Simultaneously, observed from the CIE (Commission International del’Eclairage) chromaticity coordinates, the range of the samples' luminescence color variation expanded with the Cit 3− /Re 3+ increases.