Acceptor–acceptor type isoindigo-based copolymers for high-performance n-channel field-effect transistors†
Two acceptor–acceptor (A–A) type copolymers (PIIG-BT and PIIG-TPD) with backbones composed exclusively of electron-deficient units are designed and synthesized. Both copolymers show unipolar n-type operations. In particular, PIIG-BT shows electron mobility of up to 0.22 cm2 V−1 s−1. This is a record value for n-type copolymers based on lactam cores.