Study On Flexible Organic Photovoltaic And Light-emitting Device Based On Silver Nanowires/Polyimide Electrode

Transparent conductive films(TCFs)have high transmittance and high electrical conductivity,which are widely used in solar cells,light-emitting diodes,flat panel displays and so on.With the miniaturization and lightness of electronic devices,researches on organic optoelectronic devices based on flexible substrates have attracted widespread attention.The traditional conductive ITO film has excellent photoelectric properties,however,it is brittle and requires magnetron sputtering which is high cost.In addition,as the reserves of indium on the earth decreases,the cost of ITO itself should be increased,which further limits its application in flexible devices.In recent years,many excellent materials have been emerged to replace ITO,such as graphene,carbon nanotubes,conductive polymers,and metal nanowires.In these materials,silver nanowire films have the advantages of high transmittance,low resistance,flexibility,low cost,etc.Therefore,researches on organic optoelectronic devices based on silver nanowire substrates have become particularly important and urgent.In this paper,a composite conductive film of silver nanowires and polyimide is prepared by a simple stripping technique,with an excellent figure of merit(FOM)between 67.1 and 185.1.According to the images of atomic force microscope,the film has a root mean square roughness of only 4.33 nm.In addition,the square resistance of the film is increased by only 9%after 3000 bending.The results presents this composite conductive film can be used as the transparent electrode in organic optoelectronics devices.First,we applied it to organic polymer solar cells(PSCs).By preparing inverted and normal devices,it is found that this film can be used as either a cathode or an anode.The power conversion efficiencies(PCEs)of the inverted and normal device are 5.87%±0.3%and 3.26%±0.06%,respectively,which are comparable to those of the control ITO devices.In order to verify the possibility in production,this composite conductive film is also used in doctor-blading PSC devices.The PCEs of small-area and large-area devices are 3.89%±0.12%and 1.46%±0.23%,respectively,which are 22.1%and 12.4%lower than the corresponding control ITO devices.Moreover,the application of this composite conductive film in semitransparent polymer solar cells is studied.The PCE of the semitransparent device.reaches 2.58±0.02%with the average transmittance of 36.3%.The above results show that the silver nanowire polyimide composite conductive film has a very good application prospect in the organic photovoltaic field.Finally,the application of the composite conductive film in blue organic light-emitting diode(OLED)is also studied.A high-performance blue OLED device is obtained with a maximum brightness(Lmax)and maximum luminance efficiency(LEmax)as well as maximum external quantum efficiency(EQEmax)of 3489 cd/m2 and 2.74 cd/A as well as 3.42%,respectively,which are comparable to the control ITO device.The results indicate that the composite conductive film also has a broad application prospect in organic light-emitting field.