Effects Of Bending And Torision On Resistive Switching Of Molecular Thin Films Embedded With Nanoparticles

Generally,the organic flexible devices have been intensively investigated owing to their advantages of flexibility,low fabrication cost,light-weight and large-area fabrication.However,lots of problems still need to be resolved.The existing organic flexible devices generally have low current On/Off ratio,short rentention time and unresistant to bending and torision which can hardly meet the application requirements of the partical use.To understand the effects of bending and torision on resistive switching,this paper mainly studied the influences of bengding and torision effects on the resistive switching and surface topography by various combinations of nanoparticles(NPs)and organic.The effects of process conditions including the surface topograph chang by Atomic force microscopy(AFM)and the bending and torision influence of switch ratio and threshold voltage.The contents and conclusions are as the following:Firstly,different composite thin films were built by embedding Alq3 and ZnO NPs in Polymethylmethacrylate(PMMA),Polyvinylcarbazole(PVK),Poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(benzo[2,1,3]thiadia-zol-4,8-diyl)](PFBT)films to explore the effects of bending times on the resistive switching.The results show that the electrical switching depends largely on bending times.After bending 1000 times the switch ratio one orders of magnititude smaller than unbent film.The PVK:Alq3 composite film lost the original function after bending 600 times.The bending process break the original charge transport channel,the rupture and stack of the film has influenced the NPs catch and release the charge.All of these reasons lead to the increase of resistance,the reduce of ON current,the reduce of ON/OFF ratio.Secondly,using different preparation methods to prepare the films,study the spin-coating method and spray method effects on the switching.The results show that the spray films have better flexural endurance than spin coating films.The spray films have uniform film thickness,dense surface,free from pollution preparation.Comparing the switch ratio and threshold voltage of spray films and spin-coating films,after bending the spray films' swich ratio one orders of magnititude higher than spin-coating films.Even after 2000 times bengding,the spray films still maintained a stable swich ratio.To the contrary,the spin-coating films after bending 1000 times,the switch ratio decvation increasing and the order of magnitudes drop to 101 from 103.Finally,we study the torsion influence on the resistive switching of PFBT:ZnO NPs composite films.By comparing the electrical properties of films after bending and torsion,respectively.The results show that torsion process have more influence on electrical properties.After 2000 times bending,the ON/OFF ratio decline from 4448 to 1623.But after 10 times torision,the ON/OFF ratio decline to 500.During the bending progress,the films only under tensile stress.During the torsion progress,the films under the composition of tensile stress,pressure stress and torsion.The surface of the films appeared rift and pile,all of these influence the electrical properties.