| 초록 |
We synthesized three new planar aromatic backbone molecules (Eh-Hex, Eh-Eh, and Oct-Eh), where the appended alkyl side chains on the aromatic core unit are either 2-ethyl hexyl (Eh) or n-octyl (Oct) and those on the side ends are either Eh or hexyl (Hex). Molecular film characterizations revealed that all the molecules were crystalline and assumed mainly edge-on orientation, while the molecules (Eh-Hex, Eh-Eh) manifested higher crystallinity than the molecule (Oct-Eh). In molecule:PC71BM blend films only the Eh-Hex molecule exhibited a good intermolecular packing and formed uniformly distributed nanoscopic networks of molecular channels, maintaining high interfacial contacts between the Eh-Hex and PC71BM domains. In contrast, the Eh-Eh molecules showed poor miscibility with PC71BM and the Oct-Eh molecules displayed too much miscibility with PC71BM molecules. These differences resulted in the significant differences in the photovoltaic performance of the molecule:PC71BM blend devices. |
