Fabrication And Stability Performance Of Silver Nanowire Transparent Conductive Films

Silver nanowire transparent conductive films(AgNW TCFs)have great application prospects in optoelectronic devices such as touch panels,displays,solar cells,heaters,and so on.However,AgNW TCFs will suffer from negative effects in practical applications due to electrical,thermal,and air aging instability issues and poor adhesion problem.These factors greatly limit the real-world application of AgNW TCFs.Therefore,this thesis aims at the application of AgNW TCFs,focusing on the instability mechanism of AgNWs.The stability of AgNW transparent conductive thin films has been studied and explored.The research contents mainly include the following aspects:(1)Focused on the weatherability of AgNW TCFs,a mild,efficient and low-cost method of treating AgNW TCFs with dilute solution of ferric chloride was proposed,which improved the weatherability of AgNW TCFs,including air aging,thermal aging,acid-base reagents and mechanical stability.The improvement of weatherability is due to the protection of thin AgCl layer formed on the surface of AgNWs.Typically,the size-dependent instability of AgNWs has been fully explored and explained in terms of the related processes of surface atomic diffusion.The chemical adsorption-related fermi level shift of AgNWs was used to regulate the chemical reaction of AgNWs to ferric chloride solution in order to balance the size-dependent stability of AgNWs and maintain the relationship between their photoelectric properties.(2)Focused on the poor adhesion and low hardness of AgNW TCFs,a sandwich structured bottom hard coat/AgNWs/top hard coat TCF has been prepared by embedding AgNW layer between two hard coat layers.The film exhibits excellent scratch resistance and 3 H hardness.In addition,the hardened AgNW TCFs exhibit excellent optical,air aging resistance and mechanical stability.Compared with the bare AgNW TCFs,the haze of the films decreased from 1.4%to 1%at 550 nn,and the decrease was as high as 28%without sacrificing the transmittance.Because of the gas blocking characteristics of the hardened layer,the resistance of the hardened AgNW TCFs remained almost unchanged during 90 days of aging test.(3)Focused on the electrical and thermal instability of AgNW TCF electrodes,we explored the breakdown mechanism of AgNW networks with different resistance,distinguished the breakdown of electrothermal and electromigration,and the breakdown theoretical models of AgNW TCF with different resistances were established.Experiment results showed that the surface density,electric field strength,heat transfer rate and thermal stress migration affect the breakdown of AgNW TCF electrodes.For low resistance AgNW electrodes,the breakdown is mainly caused by Joule effect.When it comes to the AgNW network with medium resistance,the breakdown is jointly caused by Joule effect and electromigration.For high resistance silver nanowire electrodes,the breakdown is attributed to current crowding effect and electromigration caused by electric field force.Furthermore,we proposed a method to suppress the electrical and thermal breakdown of AgNW TCFs by atomic layer deposition of zinc oxide on the surface of AgNWs.(4)Based on the mechanism of electrical and thermal breakdown of AgNW TCF electrodes,we studied the feasibility of Terahertz continuous dynamic spectroscopy assisted detection of the breakdown mechanism of AgNW TCF heaters.This will enable us to understand the dynamic process of breakdown of AgNW TCF electrodes at high power density,such as the sequence of action of electrical and thermal effects,which is the dominant role of the two and the synergy or constraints interaction between them.In addition,the experimental results show that the electrical and thermal breakdown of AgNW TCF electrode is quantized at high power density.In conclusion,it is of great guiding significance to formulate the corresponding control strategies to suppress the breakdown of AgNW TCFs.