Enhancing Stretchability of PEDOT:PSS Films with Ionic Liquid Pretreatment: A Molecular Dynamics Study

Abstract

Poly(3,4-ethylenedioxythiophene):poly(stryrenesulfonate) (PEDOT:PSS) is the most promising material for stretchable electronic components because it is stable, transparent and solution processable. However, the pristine PEDOT:PSS thin film has limited electrical conductivity (<10 S/cm) and low yield strain (<6%). The electrical conductivity and stretchability of pristine PEDOT:PSS films can be improved by ionic liquid (IL). We investigate the effect of ILs on the PEDOT:PSS morphology through molecular dynamics simulations of the mechanical properties of PEDOT:PSS subjected to uniaxial strain. Through this, we observe at the molecular level how the morphology change by the IL can improve the stretchability of the PEDOT:PSS. Finally, the principle of improving the electrical and mechanical properties of PEDOT:PSS of the IL is identified, and the design principle of the IL is proposed to control the desired properties.