Photoluminescence And Luminescence Mechanism Pulmonary Of RE (Tb³⁺, Gd³⁺) Doped Titania Film

The humanity was regarding luminescent material's development and the research had more than 100 years history, during this process the people have made the unceasing breakthrough and the progress, causes the luminescent material the illumination performance to be more outstanding, the variety is more complete, the application domain is broader. Along with luminescent material's unceasing development, based on the luminescent material related research, the manufacture and the application also gradually emerges, such as illumination ceramics, luminescent glass, luminous paint and so on. The rare earth material application is widespread, such as the light information transmission, the solar energy electro-optic transform, X-ray phantom and so on. From the practical application angle, TiO₂ takes one kind to use for to dope the rare-earth element the fine matrix material, it has the superior optics and thermodynamics performance as well as has the good stable characteristic in many corrosive environment.The article using Ti(OBu)₄, take rare earth Tb, Gd as the activating agent, has prepared the TiO₂ nanometer thin film which a series of rare earth co-dopes by sol-gel. Using modern analysis test technologies, such as XRD, TG/DTA, IR, TEM and PLE, PL spectrum, has carried on the attribute to luminescent material's characteristic, has studied the material's influencing factor and the luminescent mechanism. The goal is seeking for the preparation practical, moderately-priced, the performance good new luminescent material.1. Has prepared the rare earth doping TiO₂ nanometer thin film, studied the different factor to the craft the influence, determined the best technological conditions. H₂O/ Ti(OBu)₄ best scope between 1-4; C₂H₅OH/ Ti(OBu)₄ best scope between 3-10; pH in 4; The heat treatment temperature is 500℃.2. Has carried on a series of tests to the TiO₂ thin film sample, such as XRD, TG/DTA, IR, TEM. According to the analysis result, indicated that the TiO₂ thin film is the anatase, the surface to be smooth, the average size approximately is about 15nm.3. Through to research the Tb³⁺-doped TiO₂ thin film sample's PLE, PL spectrum's analysis, has analyzed its luminescent principle. The cross relaxation between ⁵D₃-⁵D₄ and ⁷F₆-⁷F_1,0, which is the main reason of lower emission intensity of ⁵D₃-⁷F_j (j =5, 4, 3) than ⁵D₄-⁷F_j (j=6, 5, 4, 3) transition. The transitions from ⁵D₄-⁷F_j (j =6, 5, 4, 3) are radiative and correspond to the emission lines of 493, 550, 590 and 624 nm, respectively. Photoluminescence (PL) intensity is found to have a well matching relation with the doping concentration of Tb³⁺ ions. Concentration quenching of PL occurs when Tb³⁺ concentration exceeds a certain value.4. Research the co-doped Tb³⁺ and Gd³⁺ TiO₂ thin film sample's PL spectrum. Luminescence intensity is improved obviously after co-doped with Gd³⁺ ions because of the sensitization effect of Gd ³⁺ ions. As a result of the energy level match's reason, is carries on Gd³⁺ to the Tb³⁺ energy transfer by the non-radiation way. Along with Gd³⁺ density's increase, energy transfer's probability increases, the sample photoluminescence intensity enhancement.