| 초록 |
During nanoimprinting process to introduce nanostructures on an active layer of polymer solar cells, the capillary force in confined molds plays a critical role in polymer crystallization and phase separation of the bulk heterojunction film. In our experiments, the nanoimprinting process induced enhanced polymer crystallization and multi-dimensional chain alignment of polymers for more effective charge transfer, and a fine phase-separation between polymers and PC71BM to favor exciton dissociation and increase the generation rate of charge transfer excitons. Consequently, the incorporation of periodic nanostructures on PTB7: PC71BM and PTB7-Th:PC71BM increases the power conversion efficiency by approximately 15 % and 28 % with increased current density (Jsc) and fill factor (FF), respectively. In this study, we demonstrate the effects of a nanopatterned active layer on the electrical properties, such as internal quantum efficiency (IQE) and FF, of inverted polymer solar cells. |
