Strain-Induced Electrical Hysteresis of Organic Thin-Film Transistors in Wrinkled Conjugated Polymers

In recent years, there has been a rapid increase in interest in flexible electronics based on organic materials. Systematic studies investigating the effect of different types of defects, which occur under mechanical strain, on the electrical stability of the devices are required. However, there are not many related studies. In this study, we investigate strain-induced hysteresis caused by the formation of wrinkles in a conjugated polymer used in organic thin-film transistors. Wrinkles are formed by stretched poly(dimethylsiloxane) (PDMS) and successfully controlled by the strain applied to PDMS. Based on the electrical behavior, including drain current-gate bias(I_D-V_G) hysteresis, the results reveal that surface wrinkles affect the density of electron and hole trap sites. This behavior is phenomenologically analyzed by using atomic force microscopy. Subsequently, a novel band diagram model is developed by systematically controlling the wrinkle density. The findings provide new insights into the electrical reliability characteristics of next-generation nanoelectronics.