The Fto And Ito Thin Film Optical And Electrical Properties In Simulated Environmental Media Stability And Impact Mechanism

Transparent conductive oxide (transparent and electrically conductive oxide, referred to as TCO) film with very low resistivity (generally up to 10-3～10-4Ω·cm) and almost transparent to visible light (up to 80%), chemical stability, simple preparation, such as excellent physical and chemical properties, which in flat panel displays, solar cells, transparent electromagnetic shielding and antistatic devices, resistive touch screen as well as biological sensors have been widely used, of which fluorine doped tin oxide (F-doped tin oxides, referred to as FTO) films and doped indium tin oxide (Indium doped tin oxides, referred to as ITO) film is currently in the components of the two most widely used transparent conductive thin film electrodes.In recent years, with the continued application of industrial technology, microelectronics and development, more and more films based on actual working conditions of electronic components required in some harsh environments, such as moisture vapor environment, high temperature environment, the chemical industry environment, and some special needs of the environment. Although these components in the course of the surface were usually coated with a protective coating or packaging material, but because the ion has a strong media corrosion penetration, may penetrate the protective layer against the inside surface of the thin films produced corrosion, physical and chemical properties make thin films of change. Severe corrosion will result in performance degradation of electronic components or failure phenomenon occurs. As in the original of most of the two types of transparent conductive thin film electrodes, FTO and ITO films also face these issues. Therefore, the study of FTO and ITO films in various simulated environmental media and optical properties of stability and degradation mechanism has the very important practical significance.Against this background, this thesis is about NaCl, Na2SO4, NaOH, H2SO4 solution to simulate different environmental media, studied by immersion test and the ITO film FTO environment in the optical and electrical properties of the law, and then through the electrochemical pole of curves and scanning electron microscopy (SEM) were used to analyze the degradation mechanism of thin film optical properties and influencing factors. FTO films according to the solution of these four changes of medium, the relative resistance values and visible light with the known variation of immersion time, with the immersion time the value of the relative resistance change film increases, transmittance decreased show that the electrical and optical properties of thin films have emerged degradation phenomena. With the solution temperature increasing, the electrical and optical properties of thin film degradate of even more significance. FTO film in the optical properties of four aqueous solutions, the stability of the best in the Na2SO4 solution, the worst in the NaOH solution. FTO thin film optical and electrical properties degradation occurs mainly due to the corrosive effect of the solution medium led to the formation of films starting when the destruction of dense oxide layer of protection, and in the course of follow-up of corrosion protection is difficult to re-form a dense layer, can not produce to prevent further corrosion effect, the electrochemical results validates the above reasons.The same with the FTO film, ITO film in the above-mentioned four kinds of aqueous solutions, with the immersion time has also appeared in films increased the relative change in resistance value, the deterioration of the performance degradation of transmission, but as the solution temperature increased, the film The degradation of electrical and optical properties are more significant. However, films with different FTO, ITO thin film stability and optical properties of NaOH solution at best, the worst in the H2SO4 solution. ITO thin films in aqueous solutions, optical and electrical properties of deterioration occurs because the same with the FTO film is formed when the initial film surface as the dense oxide layer of protection has been corrosion damage, corrosion can not stop the further production role.By comparing with FTO and ITO films in NaOH and H2SO4 solution, the stability of optical properties of comparison known, FTO in H2SO4 solution is better than the stability of optical properties of ITO films, and in the NaOH solution is poor than the stability and optical properties of ITO thin films.