High-Performance Vinyl-flanked Diketopyrrolopyrrole-Selenophene Polymer Semiconductors with Branching, Linear and Cyclic Alkyl Side Chains

Abstract

Vinyl-containing conjugated polymers exhibiting extended conjugated skeletons with long-wavelength absorption and high carrier mobility have been widely investigated as polymer semiconductors. However, a new vinyl-flanked diketopyrrolopyrrole (DPP) unit with the vinyl groups directly connecting at 3,6-positions of the DPP core has rarely received attention. Herein, we reported three semiconducting polymers (PDPPTSe, PDPPTSe12 and PDPPTSeCyH in Scheme 1c) containing vinyl-flanked DPP and selenophene units with branching, linear or cyclic alkyl side chains. PDPPTSe12 with a linear side chain exhibits a high hole mobility of 6.76 cm2V-1s-1, which can be attributed to the high crystallinity of its thin film, tight π-π stacking and better interchain packing orientation in comparison with PDPPTSe. On the contrary, the hole mobility of PDPPTSeCyH with a cyclohexyl side chain is only 0.83 cm2V-1s-1 because of the large π-π distance, low solubility and low crystallinity. This work reveals the vinyl-flanked DPP unit is a useful building block to obtain high-mobility polymer semiconductors through side-chain modifications.