Study On The Preparation And The Coated Film Performance Of Long Silver Nanowires

With the development of science and technology, the material with high conductivity and transmittance has become an important composition of many photoelectric devices. As is known to all, Indium tin oxide(ITO)transparent conductive films have been utilized to produce photo electronic devices for fifty years. But owing to the lack of raw material as well as its poor performance of flexibility, ITO can't meet the needs of the latest generation of photo electronic devices, which are good portability, high flexibility, low price and preparation of large-area. Because of its good properties, such as electrical conductivity, visible light transmittance and flexibility, silver nanowire transparent conductive films have become a hot topic in flexible electronics field. The conductivity and visible light transmittance of flexible transparent conductive films are related to the aspect ratio of silver nanowires, so the use of silver nanowires with high aspect ratio is more conducive to enhance the overall performance of the silver nanowire transparent conductive films.The article is based on the producing principle of silver nanowires prepared by polyol method, using one-step method to carry out the experiment by a modified polyol method. The results show that ultra-long silver nanowires could be successfully prepared by the improved polyol method, in which ethylene glycol was used as the reducing agent and solvent, polyvinyl pyrrolidone(PVP)as a stabilizer and inducing agents, silver nitrate as a precursor and ferric chloride as a control agent. The article includes the research of the influence of multiple experimental variables on the growth process of silver nanowires through using control variable method. The multiple experimental variables contain molar ratio of PVP to silver nitrate, the concentration of ferric chloride and reaction temperature. Finally it could control the producing of silver nanowires successfully. By adjusting the experimental variables, ultra-long silver nanowires could be obtained, with which length reached 150 ?m and aspect ratio reached 1000.The transparent conductive film is fabricated by the use of ultra-long silver nanowires obtained in the experiment. The silver nanowires were coated into film on the glass by five coating method, drop-coating, spin-coating, spraying, Meyer rods coating and capillary force spreading. With the morphology and property of the thin films produced by different coating methods having been researched, the relationship between electrical conductivity and visible light transmittance was studied to get a more practical coating method. Based on that, an acid treatment was carried on the surface of silver nanowire transparent conductive film. It showed that the surface resistance of the film decreased from 40 ?/sq to 11 ?/sq, while the visible light transmittance remained unchanged(about 86%)after the acid treatment. Above all, the properties of silver nanowire transparent conductive film can be compared to that of ITO. And silver nanowires can be a hot alternative to replace ITO as the next generation of flexible transparent conductive material.