High-Lamellar Ordering and Amorphous-Like π-Network in Short-Chain Thiazolothiazole−Thiophene Copolymers Lead to High Mobilities

Owing to their superior transport properties, poly(alkylthiophenes) and their derivatives emerged as one of the most widely studied semiconducting polymers with potential applications in organic electronics. It is now generally acknowledged that one of the particularly effective ways to increase the carrier mobility in these materials is by increasing the length of the conjugated backbones. Some recent reports suggest also that carrier mobilities can be further enhanced by highly crystalline arrangement (and interdigitation) of alkyl side chains possibly because it promotes the formation of extensive layered structures favorable for carrier transport. Results presented here demonstrate that, surprisingly, none of these factors are actually necessary for good electronic performance of polythiophene-like systems. Thiophene-based semiconducting polymers bearing thiazolothiazole unit (PTzQT) described here were shown to have very high carrier mobilities (∼0.3 cm2/Vs) despite their low molecular weight and une...