Preparation And Properties Of Rare-earth-doped Titanium Dioxide Nano-light-emitting Materials

Using tetrabutyl titanate as precursor, Eu3+ doped TiO2 nano-powder or films were prepared by the sol-gel process and the hydrothermal synthesis method. The morphology, composition and properties of samples were characterized by scanning electron microscope (SEM), EDS, and PL spectrum etc. The effect of annealing temperature, doping concentration of Eu3+, content of ethanol solvent and alkali etc. on the luminescent property of Eu3+ doped TiO2 were investigated. The mechanism of luminescence was studied.The particles size of rare earth Eu3+ doped TiO2 nanocrystalline sample is about 30-80nm.The EDS energy spectrum shows that the Ti:O atom rate of the sample does not meet the number by chemical measurement which is 1:2. The oxygen space formed when the Eu3+ ion replace the Ti4+ ions, which indicate that rare earth Eu3+ ions enter into the lattice of TiO2. The strongest emission peak of the sample lies in 614nm which instead of the 5Doâ†'7F2 transition and the magnetic dipole transition 5D0â†'7F1 lies in 595nm; simultaneously, the emission peak 578nm(5D0â†'7F0),652nm(5D0â†'7F3),700nm(5D0â†'7F4)appeared. When the condition of component, annealing temperature and the amount of ethanol solvent, catalyst is different, the emission spectrum of TiO2:Eu3+ nanocrystalline will be different.When Eu3+ and Ce3+ ions mixed together, the blue emission of Eu2+ realized. In the preparation of the thin film, each coating layer must be heated and annealed at 500℃, the crystallization effect of the film is good, and the 578nm (5D0â†'7F0) emission peak appeared.When the excitation wavelength is 464nm,414nm,395nm,382nm,272nm, as for the thin film, the highest luminous efficiency at 614nm respond to the excitation wavelength is 395nm. The joinment of Al3+ realized the Eu2+ blue emission of the TiO2:Eu3+ thin film when the annealing is 900℃, and proved in the environment of high temperature, Al3+ can reduce Eu3+ to Eu2+ ions.The xerogels and thin films were prepared by the hydrothermal method. The reaction temperature, Al3+ doping have influence on the emission intensity of the samples. The NaOH solution changed the crystal structure of TiO2 matrix, and increased the absorption of samples in the uv region.