Study On The Preparations And Properties Of The Flexible Transparent Electrodes Based On Ultra-thin Silver Films

The rapid development of flexible optoelectronic devices puts forward higher requirements for transparent electrodes,while having high electrical conductivity and optical transmittance,as well as excellent mechanical flexibility and performance stability under long-term service conditions.The traditional transparent conductive electrode indium tin oxide(ITO)cannot meet the requirements of a flexible transparent electrode due to its high price and poor mechanical flexibility.The dielectric/metal/dielectric(D/M/D)structure flexible transparent electrode based on the ideal ultra-thin continuous Ag film has the advantages of good mechanical flexibility,high optical transmittance,and good conductivity,making it a traditional A potential replacement for transparent electrode indium tin oxide(ITO);however,due to poor wettability on the surface of the oxide substrate,it is difficult to prepare a continuous Ag film with a thickness of less than 10 nm.In this paper,by comparing the growth behavior and transparent conductivity of Ag on the surface of SiO_x,ZnO,ZnS substrates,the influence mechanism of the substrate on the growth of Ag film is studied;the transparent wetting layer is introduced to study the effect of ZnS wetting layer on Influence of growth mode of Ag film onSiO_xand ZnO surface;Finally,the ZnO_1-xS_xsubstrate was prepared by co-sputtering process,the growth mode of the top Ag film was adjusted,and the ultra-thin and ultra-smooth continuous Ag film was prepared,and the flexible transparent electrode with excellent performance of ZnO_1-xS_x/Ag/ZnO structure was developed.The main research contents are as follows:(1)By comparing the morphological evolution process of Ag film on the surface of SiO_x,ZnO and ZnS on different reactive substrates,combining the analysis of the interface structure and the analysis of the ultra-thin Ag crystal structure and surface roughness,the effect of the substrate surface structure on the ultra-thin Ag film is studied.The influence mechanism of growth mode,and the optical and electrical properties of flexible transparent electrodes with D/M/D structure on different substrates were characterized,and the structure-effect relationship between the transparent conductive properties of the electrodes and the microstructure of the Ag film was established.An Ag film with a thickness of 10 nm and a surface roughness as low as 0.75 nm is prepared on the surface of a ZnS substrate,and an ultra-thin Ag film with preferential growth on Ag(111)surface is prepared by using the ZnO substrate.The continuity of the surface morphology of the 10nm Ag film is as follows:ZnS/Ag>ZnO/Ag>SiO_x/Ag.The formation of Ag-S bonds reduces the interface energy and improves the wettability of Ag.The Ag film on the surface of the ZnO substrate has a large grain size,so the grain boundary scattering is small,and the continuous Ag film exhibits better conductivity than ZnS/Ag.(2)In order to use ZnS to improve the wettability of the Ag film while reducing the loss of optical transmittance in the ZnS layer,1nm-ZnS was introduced on the SiO_xand ZnO substrate as the wetting layer deposited by the Ag film,which greatly improved the Ag film The surface morphology is continuous and the surface roughness of the Ag film is reduced;the prepared SiO_x/ZnS/Ag/ZnO transparent electrode has an average transmittance of 89.5%and a surface resistance of 13.9?sq^-1,while the ZnO substrate The continuity of the surface morphology of the Ag film is limited after the wetting layer is introduced on the surface.Although the optical performance of the ZnO/ZnS/Ag/ZnO transparent electrode has increased to a certain extent,the electrical conductivity has decreased.(3)Integrating the different influence mechanisms of ZnO and ZnS substrates on the morphology and optical and electrical properties of the Ag film,the ZnO_1-xS_xsubstrate is prepared by co-sputtering,which reduces the critical thickness of the continuous film and promotes the growth of the Ag(111)crystal plane.Optimal growth,thereby improving the transparent conductivity of the D/M/D structure electrode.The prepared ZnO_1-xS_x/Ag/ZnO transparent electrode exhibits a transparent conductivity that is completely comparable to ITO,with an average transmittance of 91.8%and an area resistance of 12.1?sq^-1.