Preparation And Characterization Of Luminescence Film Material Of Oxide

Overview of preparation of luminescent thin film is made based on the a large amount of references at home and abroad. Human society has entered information era with the rapid development of information technology, Many new media has appeared and large amounts of high accuracy electronic product has appeared every aspects. Electronic display device has become more and more important, especially the various FPD, which has thin , light , low voltage drive, low energy consumption and adapt to the data technology.Compared with traditional display screen prepared with luminescent powder, luminescent materials of thin film have many advantages, such as excellent electric and heat conductivity, high contrast ratio, low gas release rate, uniformity, good combination with the matrix. The endurance of high temperature and large electric current are improved and heat diffusion of thin film become fast which avoid quenching of fluorescent light. So it is significant to study the preparation of fluorescent thin film and its application in various display devices.Sputtering, Pulsed Laser Deposition and Mtallorganic Chemical Vapor Deposition can control the composition of thin film and the growth orientation; it can also decrease the temperature of post treatment. The disadvantages of these method is the high cost and high equipment investment, so it is not fit to prepare large area thin film.A novel method to prepare luminescent thin film was proposed, that is electro deposition- sintering. The cost decreases sharply corresponding to the vapor phase deposition. The thickness of thin film can be adjusted by controlling the electric quantity, the preparation technology of display apparatus simplified owing to prepare luminescent materials from ITO glass. Three red luminescent materials and three green luminescent materials are obtained via electrochemical- sintering method. They are Y₂O₃:Eu, Gd₂O₃:Eu , La₂O₃:Eu respectively and Y₂O₃:Tb, Gd₂O₃:Tb, La₂O₃:Tb respectively. Their emission is the characteristic spectrum of Eu, Tb ion and is not relevant to the matrix. The luminescent range of blue and green luminescent thin film of ZnO cover 375～500nm, there are two obvious emissive peak about 396nm and 469nm, this can be attributed to ultraviolet and blue band. The effect of electrodeposition condition on luminescent strength of Y₂O₃:Eu, Y₂O₃:Tb, ZnO are studied.SEM and AFM are employed to observe the appearance morphology of thin film. The results indicate that uniformity surface is made of many small microcrystalline. The XRD of thin film indicate that the integrate of crystalline is good when treated at 500℃.Electrochemical and electrochemical quartz microbalance (EQCM) are employed to investigate the mechanism of electrodeposition of yttrium hydroxide. The results show that the deposition process of yttrium hydroxide is step by step. First hydroxyl produced from the reduction of NO₃^- on electrode, and hydroxyl reacted with yttrium absorbed in the surface of electrode to form yttrium hydroxide. Electrochemical reaction is the control step and k^θis 1.616×10^-9, High over potential is needed to accelerate the reaction owing to the small reaction rate constant.The hexamethine tetramine and citric acid are used to prepare stable colloidal sol of Y₂O₃ doping with Eu³⁺. Inorganic salts are used to synthetic materials and change the traditional sol-gel technology which alkoxide is used as precursor. The effect of thermal treat temperature on chemical composition and the effect of technology on the preparation of thin film are studied. The properties of colloidal sol can keep 48h in ambient temperature and closed condition. Luminescent thin film Y₂O₃:Eu³⁺ are prepared with spinning coating method based on monocrystal silica slice. The alteration of crystalline structure and surfacial morphology and luminescent properties under different thermal treatment condition is investigated. The crystalline temperature of thin film lowered 200℃compared to that of high temperature solid phase method.Inorganic luminescence thin film prepared with sol-gel method have many advantages such as uniformity, no crack and compact accumulation of particles. The luminescent properties of thin film is related with the technology of solvent preparation and the varieties of additive. Compared to hexamethine tetramine, luminescent properties of thin film that incorporating citric acid is obviously lowerd, and the luminescent strength is only 73% compared to that of the former, The XRD of luminescent thin film indicates the crystalline purity of the former is superior to the latter.No crack luminescent thin film are obtained under the optimum technology when Eu contained complexes incorporating to matrix of silicon dioxide, The luminescent properties of rare earth complexes in the matrix of silicon dioxide, especially the thermal stability and the complexion of benzoic acid Eu in the matrix of silicon dioxide and the effect of concentration of doping and thermal treating temperature on luminescent properties of materials are studied. The luminescent strength is improved owing to decrease the fluorescence quenching of hydroxyl group when PEG is incorporated. Strong emission appears in 594nm and 618nm, The luminescent strength of unit mass increase double times. The analysis of XRD and atom force macrograph (AFM) show benzoic acid Eu/SiO₂ is an amorphous solid, and the good dispersion in matrix of silicon dioxide can be achieved when PEG400 doping to thin film.Electrochemical deposition and sol-gel are very good method to prepare luminescence thin film materials. Electrochemical deposition is favorable to prepare luminescence thin film materials from the conducting matrix, and sol-gel method is employed to prepare luminescence thin film materials from nonconducting matrix.