| 초록 |
We investigate the effect of atomic substitution on optical, electrical, and morphological properties of donor-acceptor (D-A) conjugated polymers. By substituting a carbon atom by C-F (CDT-FBT) or C-Cl (CDT-ClBT) functionality in the benzothiadiazole (BT) moiety, three D-A conjugated polymers have been investigated. Compared to the CDT-BT polymer, the CDT-FBT showed high crystallinity. By contrast, however, the CDT-ClBT showed enhanced dihedral angles and reduced crystallinity due to steric hindrance, thereby mitigating efficient π-π stacking between polymer chains. The CDT-FBT produced field-effect mobility similar to that of the CDT-BT, whereas the CDT-ClBT showed carrier mobility an order of magnitude lower than those of the CDT-BT and CDT-ClBT. Combined with elongated device lifetime of the CDT-FBT-based field-effect transistors, these results demonstrate fluorination of D-A conjugated polymers is an effective way to develop high-performance and air-stable polymer semiconductors. |
