Elastomer-Polymer Semiconductor Blends for High-Performance Stretchable Charge Transport Networks

An inverse relationship between mechanical ductility and mobility/molecular ordering in conjugated polymer systems was determined definitively through systematic interrogation of poly(3-hexylthiophene) (P3HT) films with varied degrees of molecular ordering and associated charge transport performance. The dilemma, whereby molecular ordering required for efficient charge transport conclusively undermines the applicability of these materials for stretchable, flexible device applications, was resolved using a polymer blend approach. Specifically, the molecular interactions between dissimilar polymer materials advantageously induced semiconducting polymer ordering into efficient pi-pi stacked fibrillar networks. Changes in the molecular environment surrounding the conjugated polymer during the elastomer curing process further facilitated development of high mobility networked semiconductor pathways. A processed P3HT: poly(dimethylsiloxane) (PDMS) composite afforded a semiconducting film that exhibits superior ductility and notable mobility versus the single-component polymer semiconductor counterpart.