dc.description.abstract | ABSTRACT
In this study, titanium dioxide thin films are deposited on ITO conductive glass substrates with chemical bath deposition (CBD). By changing concentration of boric acid, temperature of bath, number of depositon layers, temperature of annealing and different atmospheres in annealing, the distructure of crystal, surface morphology, and optical and pholoelectrochemical properties of thin films are investigated. The principle of photoelectrochemical is applied in aqueous solution by absorbing solar energy and to convert water into hydrogen, which can then be used in electric generating systems.
It is found that hydroxide ions would be exceeded if concentration of boric acid increases. It would affect the growth of titanium dioxide thin film and result in corrosion and poor forming property of thin films, and the corresponding photocurrent would be thus reduced. The crystaling strength is increased as the number of deposition layers increases. Since the thin film structure is formed, the deposition rate would be decreased as the number of deposition layers achieves in some extent and the surface would be rougher. If the annealing is operated in the vacuum atmosphere, the thin film is unable to form titanium dioxide completely because of the lack of oxygen. Moreover, the influences of annealing and bath temperature are also discussed. The results showed that photocurrent has a better value at the circumstance as following: 0.05M of boric acid concentration, 90℃ of bath temperature, 2 of the number of deposition layers, 500℃ of annealing temperature and air of annealing atmosphere. The photocurrent is 126µA/cm^2, i.e. 0.126 mA/cm^2, without applying bias voltage.
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