Study On The Preparation And Properties Of The Modified TiO₂ Thin Films

Electrochromism?EC?is defined as a reversible change in the stable color by electrochemical oxidation or reduction.Electrochromic materials which have the electrochromic properties can be divided into inorganic and organic materials.Electrochromic device is generally composed of five parts:transparent conductive layer/electrode/ionic conductor/transparent conductive layer.The main function of electrochromic devices performances as adjustable transmission,reflection adjustable,information display,the application,which can be divided into smart window,glare-free mirror,electrochromic displays.In this paper TiO₂ thin films and a series of La,Nd,Bi doped TiO₂ thin films,tetrabutyl titanate and water as raw material,ethanol as solvent,acetic acid and nitric acid as chelating agent,was successfully prepared on ITO glass substrate by sol-gel method.The structure,composition,electrochemical properties and optical properties of TiO₂ were studied by means of TG-DTA,XRD,XPS,electrochemical workstation,UV-vis spectrophotometer.The results show as:TiO₂ dry gels formed of anatase TiO₂ under the 400?;500?,600? roasting treatment,respectively,and the higher the temperature,the more complete the crystal development.Due to metal ions into the TiO₂ lattice,the bond angle and bond length of La,Nd,Bi doped TiO₂ octahedron were greatly distorted,which increased the disorder of the Ti02 octahedron,resulting in the increase of the degree of amorphous phase.TiO₂ thin films with 12%of tetrabutyl titanate possess excellent electrochemic properties,and the properties were decreased when the content of tetrabutyl titanate was higher or lower than 12%.Coating layers have only a slight effect on the peak shape and peak position of the cyclic voltammetry curves.TiO₂ thin films under the 400? and 500? roasting treatment have excellent electrochemical properties,but the adhesion between film and surface of ITO glass is weak when the heat treatment is reduced to 400?.8%La,18%Nd,6%Bi doped TiO₂ thin films possess excellent electrochemic properties,and the three kinds of doping effect is compared to:Bi<La<Nd.La,Nd,Bi Co-doped TiO₂ is anatase which has a very high degree of amorphous phase,it possesses the highest degree of amorphous phase when La:Nd:Bi=4:10:2,corresponding to the best cyclic voltammetry characteristics.Undoped,La,Nd,Bi doped TiO₂ thin films have little effect on the current response time.