| With the progress of science and technology,optoelectronic devices are developing in the direction of miniaturization,lightness and foldability.The flexible transparent conductive film(TCF)is the general trend and has a good application prospect in industrial production.Tin-doped indium oxide(ITO)has been widely used in commercial TCFs.However,due to indium resources scarcity,high process cost,high deposition temperature,and especially its intrinsic brittleness,the usage of ITO will be seriously limited in emerging flexible optoelectronic devices.Recently,emerging conductive film materials have been paid wide attention.Among them,silver nanowires(AgNWs)possessing excellent optical and electrical properties,high mechanical robustness,good flexibility and comparatively high chemical stability are regarded as the most promising alternative.This work mainly studies AgNW films self-assembly on flexible substrates and develops new methods to improve optoelectronic performance of conductive films.Furthermore,this work explores AgNW film as an electrode application in flexible optoelectronic devices.Because the traditional methods encounter a problem that the film is only deposited on flat substrates with regular shape.Thus,this research reports a novel self-assembly technology to deposit AgNW networks on substrates.Through immersing the modified poly(ethylene terephthalate)(PET)with positively charged functional group into the AgNW dispersion with anionic dispersant,a flexible AgNW TCF is constituted by electrostatic adsorption self-assembly process.The as-prepared flexible AgNW film exhibits excellent optoelectrical property,low surface roughness and high reliability.In addition,this preparation method can be suitable for an arbitrary shaped substrate,which will broaden the application of AgNW conductive films in optoelectronic devices.The poly vinylpyrrolidone(PVP)adsorbed onto the AgNWs during polyol synthesis will create a large junction resistance and decrease the optoelectrical performance of the conductive film,thereby restricting its immediate application.Therefore,this work explores new methods to solve this problem.An ion bombardment method is proposed to remove the non-conductive dispersant on the AgNWs.Through a high-energy argon ion beam with enough high energy bombarding the surface of the conductive film,the non-conductive layer on the surface can be effectively removed without damaging the network,which will significantly improve the optoelectronic performance.Meanwhile,a PVP-free method is developed to produce pure AgNWs with high yield.A highly conductive polymer is utilized to ensure uniform dispersion of the AgNWs.Without any posttreatment,the sheet resistance of AgNW conductive film is 19.4 Ω/sq.when the optical transmittance is 86%,being nearly close to commercial ITO.To explore their potential in flexible optoelectronic devices,a transparent film heater is constructed based on the present AgNW networks.The heater can achieve rapid response at low input voltage and reach a relatively high temperature in a short response time.The above AgNW conductive film is used as a counter electrode substrate to build flexible dye-sensitized solar cells(DSSC).Compared with traditional ITO substrates,AgNWs with high specific surface area can enhance the adhesion between the catalytic layer and the substrate.When the thickness of the carbon layer is 102.2μm,the charge transfer resistance of carbon/AgNWs counter electrode with UV irradiation one hour is 0.2Ω·cm2.The value is much smaller than that of carbon counter electrode reported in literature.And the conversion efficiency of the corresponding DSSC reaches to 5.9%.According to the electrochemical impedance spectroscopy(EIS)and Tafel curve,it can be seen that the catalytic performance of this counter electrode are better than that of platinum electrodes.In addition,this electrode has low production cost and simple process.These results prove that the carbon/AgNWs counter electrode has promising prospects in flexible DSSC. |
PDF Full Text Request