A study on fabrication, characterization and application of TiO2 and TiO2-SiO2 thin films

• Main Authors: Kuo-PengChuang, 莊國鵬
• Other Authors: Chen-Kuei Chung
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/76672483534907898055

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 100 === Titanium oxide (TiOx) and titanium-silicon oxide (TiOx-SiO1-x) thin films were fabricated by sol gel process with various solution ratios and deposited on the Si (1 0 0) wafers by spin coating. Instead and compare of conventional furnace annealing at 500 and 800 ℃, the CO2 laser annealing was performed using with three different powers : 0.5 W, 1.0 W and 1.5 W in atmosphere. The thin films properties like microstructure, surface morphology, element atom ratios, bonding form and luminescence behaviors were analyzed by grazing incidence X-ray diffraction (GIXRD), field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), fourier transform infrared spectroscopy (FTIR) and photoluminescence spectroscopy (PL), respectively. The photocatalytic and photo-induced hydrophility were experinment to confirm the past researches. All of as-deposited TiOx and TiOx-SiO1-x thin films were amorphous phase from GIXRD analysis. The single phase of anatase and rutile were formed after furnace annealing at 500 and 800 ℃. All of thin films were also amorphous phase in laser annealed at power of 0.5 W. Only double the molar ratio of procedure and dop with SiO1-x had mix phase of anatase and rutile at power of 1.0 W, other samples and laser annealed at power of 1.5 W were only rutile crystal structure. All of the as-deposited films had distinct peak at 550 nm in PL spectra, and the TiOx thin films only had the lattice emitted itself in the near ultraviolet range after furnace annealing. It is obviously different in laser annealed, because the luminescence zone was expanded from ultraviolet range to the visible range after laser annealing. In mix crystal phase, except for the anatase and rutile lattice emission itself, also found a peak at 588 nm which was attributed to the deep-level emissions like oxygen vacancies of rutile phase and another peak at 611 nm which was due to the electron transitions related to defects or surface state energy levels emissions. The red-shift of PL peak induced with increasing power was attributed to the phase transformation with distortion of band gap junction on crystallite structure, and blue-shift was due to the SiO1-x dopped to change the lattice structure. In aplications, the best photocatalytic behavior is the thin film which has the best crystal structure. But when the power increased, the photocatalytic was related the reactive surface area. In photo-induced hydrophility, there was no influence of contact angle with changing the molar ratios in TiOx solution. But when SiO1-x dopped, the contact angles were lower than the pure TiOx thin films after UV irradiation, it is related to the oxygen content and surface acid.