Influence the host lattices on photoluminescent properties of the Ce/Tb doped CaF2, NaYF4, and NaGdF4 nanoparticles

Abstract

Ce3+/Tb3+ ions doped CaF2, NaYF4, and NaGdF4 nanoparticles (NPs) were prepared by the EDTA chelating-based thermal decomposition process. X-ray diffraction (XRD) profile shows the cubic phase in CaF2 and NaYF4 host lattice, whereas NaGdF4 in hexagonal phase, highly crystalline with an average grain size is estimated to be 20, 10, and 25 nm, respectively. Fourier transforms infrared (FTIR) spectra were employed to determine the superficial chemistry of the metal fluoride NPs. UV/Visible spectra measured in H2O solution exhibited good optical properties, and excellent colloidal stability of the luminescent NPs, implying the surface-attached organic moieties. Optical bandgap energies were estimated to determine the optical performance of the NPs. The excitation and emission spectra revealed the good photoluminescence properties of the respective host matrices. In a comparative analysis, CaF2:Ce/Tb NPs host lattice revealed efficient charge transmission from Ca2+ to the activator Tb3+ resulting in observed emission transitions of the Tb3+-ions are remarkably high luminescence efficiencies. The lifetime estimated for the Ce3+/Tb3+-doped CaF2, NaYF4, and NaGdF4 NPs is found to be 7.32, 4.169, and 4.81 ms, respectively. These findings show that the synthesized luminescent NPs presented novel luminescent properties in which CaF2:Ce/Tb NPs produce remarkable crystallinity and photoluminescent properties to be highly useful in fluorescent-based biomedical and technological applications.