• DOI:10.1038/NPHOTON.2009.192
• Corpus ID: 32746104

Polymer solar cells with enhanced open-circuit voltage and efficiency

@article{Chen2009PolymerSC,
  title={Polymer solar cells with enhanced open-circuit voltage and efficiency},
  author={Hsiang‐Yu Chen and Jianhui Hou and Shaoqing Zhang and Yongye Liang and Guanwen Yang and Yang Yang and Luping Yu and Yue Wu and Gang Li},
  journal={Nature Photonics},
  year={2009},
  volume={3},
  pages={649-653}
}

• Hsiang‐Yu Chen, Jianhui Hou, +6 authors Gang Li
• Published 1 November 2009
• Materials Science, Engineering
• Nature Photonics

Following the development of the bulk heterojunction1 structure, recent years have seen a dramatic improvement in the efficiency of polymer solar cells. Maximizing the open-circuit voltage in a low-bandgap polymer is one of the critical factors towards enabling high-efficiency solar cells. Study of the relation between open-circuit voltage and the energy levels of the donor/acceptor2 in bulk heterojunction polymer solar cells has stimulated interest in modifying the open-circuit voltage by tuning the energy levels of polymers3. Here, we show that the open-circuit voltage of polymer solar cells constructed based on the structure of a low-bandgap polymer, PBDTTT4, can be tuned, step by step, using different functional groups, to achieve values as high as 0.76 V. This increased open-circuit voltage combined with a high short-circuit current density results in a polymer solar cell with a power conversion efficiency as high as 6.77%, as certified by the National Renewable Energy Laboratory. Adding electron-withdrawing groups to the backbone of the polymer PBDTTT is shown to increase the open-circuit voltage of photovoltaic cells, resulting in a polymer solar-cell that has a certified power-conversion efficiency of 6.77%.