초록 |
Quinoxaline (Qx) is promising unit for efficient photovoltaic polymers owing to their strong light absorption and high charge-transport abilities, but they have been used exclusively for polymer donors. Herein, for the first time, we report Qx-based polymer acceptors (PAs) by introducing electron-withdrawing cyano (CN) groups into the Qx moiety (QxCN). A series of QxCN-based PAs, P(QxCN-T2), P(QxCN-TVT), and P(QxCN-T3), are copolymerized unit with bithiophene, (E)-1,2-di(thiophene-2-yl)ethene, and terthiophene, respectively. All of the PAs exhibit the unipolar n-type characteristics with organic field-effect transistor (OFET) mobilities of ~10−2cm2V−1s−1. In space-charge-limited current devices, P(QxCN-T2) and P(QxCN-TVT) exhibit electron mobilities greater than 1.0x10−4cm2V−1s−1, due to the well-ordered structure. When the PAs are applied in all-polymer solar cells (all-PSCs), the highest performance of 5.32% is achieved in the P(QxCN-T2)-based device. |