| 초록 |
We report on a series of 2D-benzodithiophene(BDT)-based active materials with various numbers of BDT units (1 to 3), and demonstrate that the number of 2D-BDT units is essential in creating a well-defined intermolecular interaction, and the desired interconnectivity in the bulk heterojunction. These 2D-BDT-based active materials could enhance exciton diffusion and free charge carrier transport in the organic solar cells. In BDT2, two BDT units induced strong intermolecular interaction, promoting the desired interconnected structure. This structure could enhance exciton diffusion and free-charge-carrier transport of the OSCs since BDT2 exhibited a PCE of 8.56% with a high fill factor of 0.73. The BDT2 exhibits a highly efficient, large-sized small-molecular(SM) OSC with a power-conversion efficiency of 7.45% at an area value of 77.8 cm2 . Our results provide valuable information in terms of the design strategy for fabricating high-efficiency SMs that are applicable in large-area OSCs. |
