| 초록 |
A trade-off between open-circuit voltage (Voc) and short circuit current (Jsc) is one of the problems to be solved for attaining highly efficient organic solar cells (OSCs). Herein, we report efficient and stable OSCs based on new asymmetric A-DA’D-A type nonfullerene acceptor (NFA), IPC-BEH-IC2F. It designed by replacing 2-(5,6-difluoro-3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile (IC2F) which used as an end group in Y6 with 9H-indeno[1,2-b]pyrazine-2,3-dicarbonitrile (IPC) with tricyclic ring. Due to the asymmetric IPC-BEH-IC2F, IPC-BEH-IC2F based OSC blended with PBDB-T showed a balance between Voc and Jsc, leading to a high PCE of 12.70%. In addition, the PBDB-T:IPC-BEH-IC2F based OSC exhibited good long-term stability because the IPC group promotes strong intermolecular interactions. Therefore, we demonstrate that using asymmetric NFAs can be useful for improving the photovoltaic performance and stability of OSCs. |
