Study Of Design And Optimization Of Silver Nanowires Network Based Flexible Transparent Electrode

With the development of photoelectric industry and the rise of flexible photoelectric device,such as flexible display and e-skin,traditional brittle transparent electrode(metal oxides)has been more and more difficult to meet the requirements,while flexible transparent electrode materials attract much attention.Carbon nanotubes,graphene,conductive polymer,metal mesh and metal nanowires are strong candidates for the flexible transparent electrode materials,and silver nanowires electrodes become the hot spot because of excellent electrical conductivity and light transmittance.But there still be much room for improvement of silver nanowires quality and coting process when used to photoelectric devices.Based on the silver nanowires flexible transparent electrode,we focused on the performance optimization by network structure design and nanomaterial manipulation,the main works are listed as follows:(1)The conductive and transparent mechanism are studied.From the point of structure,junction resistance is the main factors influencing the network resistance and qusi-ordered network can reduce the number of junctions,is more advantageous to directional conduction;From the material,the higher aspect ratio of silver nanowires can obtain a lower sheet resistance and higher transmittance.(2)A kind of non-contact coating method was adopted to realize the quasi-aligned silver nanowires array.This quasi-alignment is the result of pinning force from the substrate and viscous force of dispersion solution,in addition,we studied the influence of coating speed,temperature and substrate on it.Vertically crossed silver nanowires network can be obtained by multi-step coating.Compared with random silver nanowires network obtained with spray coating,the vertical structure network has more advantages in conductivity and transmittance,when used in transparent heaters,it shows better defrosting effect.(3)A top-down method by electrochemical etching is used to thin the diameter of thick silver nanowires due to its advantages of length and synthesis.By controlling the etching time and etching current,the increase of transmittance and decrease of haze could be manipulated;Besides,due to electromigration and shedding of PVP,silver nanowires are welded together at the junction area,reducing the sheet resistance of silver nanowires network.Compared with the reported flexible transparent electrode materials,the electrochemical etched silver nanowires electrode achieved better performance.When applied to bifacial the solar cells,the conversion efficiency reach to 16.0% and 11.1% with light incidence from two electrodes,respectively.