Conjugated Polymer-Mediated Polymorphism of a High Performance, Small-Molecule Organic Semiconductor with Tuned Intermolecular Interactions, Enhanced Long-Range Order, and Charge Transport

Abstract

We use 6,13-bis(triisopropylsilylethynyl)pentacene as a model small molecule organic semiconductor and two conjugated polymer additives to demonstrate conjugated polymer-mediated polymorphism of a small molecule organic semiconductor for the first time. The conjugated polymer additives, used with a slow solution crystallization approach, yield crystal structures that are not accessible by nonconjugated polymer additives and impart excellent long-range order. In both of the small molecule semiconductor/conjugated polymer blends studied here, previously unreported polymorphs of a small molecule semiconductor have been identified which also leads to improved charge transport in the absence of external alignment. These results open up a new exciting avenue to manipulate unit cell structure, long-range order, and charge transport of high performance, solution-processed, small molecule organic semiconductors.