초록 |
Organic solar cells (OSCs) based on organic bulk heterojunction films have been extensively studied and their power conversion efficiency reached ca. 18 % thanks to the extended light absorption ranges. The bulk heterojunction films can be made mostly by combining conjugated polymers and small molecules as an electron donor and an electron acceptor, respectively, while both components could be polymers or small molecules. In addition to active layers, the performance of OSCs could be noticeably improved by introducing interlayers between electrodes and active layers. The interlayers have mostly been applied on metal oxide buffer layers in the case of inverted-type OSCs at early stages, while further efforts have been carried out for both normal-type OSCs. In this presentation, it is demonstrated that combination layers, a double layer of metal oxide:polymer composites and polymers, can play a critical role in keeping the stability of OSCs. |