초록 |
The development of low-bandgap copolymers based on carbazole has attracted much attention to achieve high-performance photovoltaic cells because of the low-lying HOMO level and good thermal stability of carbazole unit. A drawback of carbazole-based copolymers is, however, low charge carrier mobility resulting from amorphous nature of the copolymers. High charge mobility of conjugated polymers is critically important for improving the performance of polymer solar cells. In order to enhance the charge mobility, the polymer chains are required to pack closely facilitating charge transport through intermolecular hopping. In this study, we report synthesis and characterization of a new class of donor-acceptor alternating copolymers comprising phenanthroline-fused indolo[3,2-a]carbazole and benzothiadiazole as an electron-donating and an electron-withdrawing unit, respectively. The photovoltaic properties of the copolymers are measured and related with their chemical structure. |