Study On Transparent Conductive Electrode For Flexible OLED

As the carrier of man-machine interaction,Display has developed from the simplest indicator lamp to today's organic light-emitting diode display?OLED?after decades of technical accumulation.Compared with the current mainstream liquid crystal display,OLED has the characteristics of self-luminescence,low power consumption,fast response and flexibility.It is almost the best choice for the next generation of display.With the development of flexible OLED from concept to product,its preparation technology and diversified applications have attracted a lot of attention.As an important part of flexible OLED,transparent conductive electrodes with excellent performance are the current research hotspot.At present,researchers have proposed a variety of flexible conductive electrodes,including conductive polymers,graphene,single-walled carbon nanotubes,metal nanowires and so on,which have good potential to replace the current mainstream OLED anode material,indium tin oxide?ITO?.However,there is a mutual restriction between light transmission and conductivity.This paper mainly studies the preparation of embedded ordered metal conductive grid and its application in OLED,mainly from the following aspects:?1?In this paper,flexible conductive electrodes are fabricated by electrochemical assisted stripping technology.Compared with other stripping methods such as wet etching,dry etching and laser assisted stripping,electrochemical assisted stripping is faster,and the surface of the sample is cleaner,which is conducive to the integration of OLED devices.At the same time,we also studied the influence of stripping voltage and electrolyte concentration on the stripping rate.The results show that bigger stripping voltage,increasing electrolyte concentration and reducing sacrificial layer area can effectively improve the stripping rate.?2?The ordered metal mesh embedded in polydimethylsiloxane?PDMS?was fabricated by Lift-off technology,and Au/PDMS flexible transparent conductive electrodes were stripped from stainless steel substrates by the electrochemical assisted stripping technology.Through theoretical design and experimental verification,the design criteria of flexible transparent conductive electrodes with good photoelectric properties are proposed.At the same time,using the prepared flexible transparent conductive electrode of Au/PDMS as anode,evaporating NPB?N,N'-diphenyl-N,N'-?1-naphthyl?-1,1'-biphenyl-4,4'-diamine?and small molecular luminescent layer Alq₃?tri?8-hydroxyquinoline?aluminum?and cathode Al,the prototype of OLED was prepared,and its luminescent properties and mechanical stability were tested.?3?In order to further improve the stretchability of flexible conductive electrodes,we propose to use U-shaped interconnected metal grid to instead the linear grid structure.Through simulation analysis,we obtained the relationship between the characteristic size and the stretchability of U-shaped interconnected structures.Using the method of?2?we have fabricated U-shaped Au grid/PDMS flexible electrodes and OLED prototypes,and discussed their photoelectric properties and mechanical stability.