| 초록 |
The photodegeneration of polymer solar cells (PSCs) based on polymer donor and fullerene acceptor limits their lifetime. Here, we demonstrate that replacing fullerene acceptors with nathphalenediimide-based n-type polymers can significantly enhance the photo-stability of PSCs. As a model system, we compared the photo-stabilities of all-polymer solar cells (all-PSCs) and fullerene-based PSCs (PCBM-PSCs) using the same polymer donor (PBDTTTPD) under one sunlight illumination. We observed a remarkable contrast in their photo-stabilities. While the fullerene-PSCs degraded significantly after irradiation for 12 h, the performance of the all-PSCs remained stable. The detailed charge dynamics show significant reduction of charge transfer and electron mobility in the PCBM-PSCs under solar illumination. In contrast, the ultrafast dynamics and electron mobility remain unchanged after illumination for all-PSCs. |
