| 초록 |
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. A drawback of carbazole-based copolymers is, however, low charge carrier mobility resulting from amorphous nature of the copolymers. For effective charge transport, the polymer chains should pack closely with each other, facilitating charge transport through intermolecular hopping. On the other hand, high VOC requires low HOMO level of donor, because VOC is proportional to the energy difference between HOMO of donor and LOMO of acceptor. In this study, we report synthesis and characterization of a new class of donor-acceptor alternating copolymers based on thiadiazole-fused indolo[3,2-a]carbazole and di(thien-2-yl)-2,1,3-benzothiadiazole as an electron-donating and an electron-withdrawing unit, respectively. The photovoltaic properties of the copolymers are measured. |
