Enhancement of PEDOT:PSS Stretchability with Ionic Liquid: A Molecular Dynamics Simulation 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%). In general, high crystallinity is required for conductivity, but this hinders elasticity. The electrical conductivity and elasticity of pristine PEDOT:PSS films can be improved by ionic liquid (IL). We observe the effect of IL on the PEDOT:PSS morphology through all atom molecular dynamics simulations of the mechanical properties of PEDOT:PSS subjected to uniaxial strain. We propose how IL improves the elasticity of PEDOT:PSS and a design principle of IL that can control the desired properties.