| 초록 |
A series of new donor-acceptor copolymers containing methylated diketopyrrolopyrrole (MDPP) were synthesized for the active layer of organic field-effect transistors (OFETs) through Stille cross-coupling with various donor units including bithiophene (PMDPP50-BT), thienylene-vinylene-thienylene (PMDPP50-TVT), and thienylene-acetylene-thienylene (PMDPP66-TAT). The performance of the OFETs strongly depended on which donor unit was copolymerized with MDPP. The PMDPP50-BT OFETs exhibited well-balanced hole and electron mobility of 0.2 ± 0.04 and 0.15 ± 0.04 cm2V-1s-1, respectively, even though their absolute mobility values were the lowest due to their high crystalline randomness and poor conjugated backbone planarity. By changing the donor unit from BT to the larger-sized TVT or TAT, both the PMDPP50-TVT and PMDPP66-TAT OFETs showed significantly improved hole mobility of 1.6 ± 0.1 and 1.25 ± 0.1 cm2V-1S-1, respectively. |
