Study On Substrate Transfer Method For Reducing Surface Roughness Of Silver Nanowires Flexible Transparent Electrodes

The transparent electrode is a material that has both high visible light transmittance and high electrical conductivity.And it widely used in flat display,solar cells and other fields.In recent years,with the development of flexible electronics and wearable devices,higher requirements have been put forward for transparent electrodes.Which not only need its excellent optical and electrical properties but also requires flexibility.Silver nanowire(AgNW)is a flexible transparent electrode material with excellent performance that can replace ITO.In this dissertation,aiming at the problem of excessive surface roughness,a substrate transfer method for reducing the silver nanowire surface roughness is studied.Its purpose is to establish the relationship between the material and process parameters,such as the areal density of the silver nanowires,the substrate carrying the silver nanowires,the mechanical pressure during the transfer,and the treatment after the transfer,and the relationship with the surface roughness of the final silver nanowire electrode.Providing a reference for silver nanowire substrate transfer method parameter optimization In addition,the paper will evaluate the effect of substrate transfer method on the electrical,optical,mechanical flexibility,substrate adhesion and thermal stability of silver nanowire electrodes,and through a certain treatment to achieve the improvement of the overall performance of silver nanowire flexible electrodes.The specifics of the paper include:(1)Using the surface-polished quartz glass as the initial substrate and polyvinyl alcohol(PVA)as the target substrate,a silver nanowire electrode substrate transfer scheme was designed,and silver nanowire electrode based on quartz glass and polyvinyl alcohol was prepared respectively.(2)The surface roughness,visible light transmittance,sheet resistance,substrate adhesion and other properties of the prepared silver nanowire electrode were analyzed and tested.The performance of the silver nanowire electrode before and after substrate transfer was compared,and the corresponding reasons were analyzed.The relationship between the silver nanowire surface density and the surface roughness of the silver nanowire electrode,the root mean square roughness,and the average roughness after the substrate transfer is clarified.(3)Polyethylene terephthalate(PET)and PVA are common substrate materials for flexible transparent electrodes.In order to compare the effect of these two kinds of substrate materials on the performance of silver nanowire electrodes,the substrate transfer method was used in this paper.The PVA/AgNW and PET/AgNW electrodes with the same surface density of silver nanowires were compared for the differences in mechanical flexibility and thermal stability,and the reasons for the differences in performance between the two were analyzed.In order to eliminate the effect of the decrease in the conductivity of the silver nanowire electrode caused by the wrapping of the target substrate,graphene oxide(GO)was used to modify the surface of the silver nanowire electrode,thereby improving the stability of the connection of the silver nanowire network.The effects of the GO solution pH value,dip coating time,and concentration on the reduction of the square resistance of the PVA/AgNW electrode were analyzed.The electrical properties of the PVA/GO/AgNW composite electrode prepared by the experimental results are improved compared to the electrical properties of the PVA/AgNW electrode.