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Tandem polymer solar cells featuring a spectrally matched low-bandgap polymer

Nature Photonics volume 6, pages 180–185 (2012)Cite this article

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Abstract

Tandem solar cells provide an effective way to harvest a broader spectrum of solar radiation by combining two or more solar cells with different absorption bands. However, for polymer solar cells, the performance of tandem devices lags behind single-layer solar cells mainly due to the lack of a suitable low-bandgap polymer. Here, we demonstrate highly efficient single and tandem polymer solar cells featuring a low-bandgap conjugated polymer (PBDTT-DPP: bandgap, ∼1.44 eV). A single-layer device based on the polymer provides a power conversion efficiency of ∼6%. When the polymer is applied to tandem solar cells, a power conversion efficiency of 8.62% is achieved, which is, to the best of our knowledge, the highest certified efficiency for a polymer solar cell to date.

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Figure 1: Molecular design, optical properties and electron density of HOMO and LUMO for PBDTT-DPP.
Figure 2: J–V characteristics and EQEs of regular and inverted single-cell devices.
Figure 3: Inverted tandem solar cells.
Figure 4: Quantum efficiencies, J–V characteristics and stability of single cells and tandem cells.
Figure 5

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Acknowledgements

This work was financially supported by the National Science Foundation (NSF, grant no. CHE0822573; programme manager: C. Foss), the Air Force Office of Scientific Research (AFOSR, grant no. FA9550-09-1-0610; programme manager: C. Lee) and the Office of Naval Research (ONR, grant no. N00014-04-1-0434; programme manager: P. Armistead), as well as by the US Department of Energy (contract no. DE-AC36-08-GO28308) together with the National Renewable Energy Laboratory. The authors thank R. Green, E. Richard, W.B. Yang and W.-C. Hsu of the Department of Materials Science and Engineering at UCLA for material testing, synthesis, ultraviolet photoelectron spectroscopy and X-ray diffraction measurements, respectively. Thanks also go to K.N. Houk and B. Martin of the Department of Chemistry (UCLA) for the quantum chemical calculation and R. Kaner and P. Weiss of the Department of Chemistry (UCLA) for reading the manuscript.

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Author notes

  1. Seiichiro Murase

    Present address: Present address: Toray Industries, Inc., Nihonbashi Mitsui Tower, 1-1, Nihonbashi-Muromachi 2-chome, Chuo-ku, Tokyo 103-8666, Japan,

  2. Letian Dou and Jingbi You: These authors contributed equally to this work

Authors and Affiliations

  1. Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, 90095, California, USA

    Letian Dou, Jingbi You, Jun Yang, Chun-Chao Chen, Youjun He, Seiichiro Murase, Gang Li & Yang Yang

  2. National Renewable Energy Laboratory, Golden, 80401, Colorado, USA

    Tom Moriarty & Keith Emery

  3. California NanoSystems Institute, University of California, Los Angeles, Los Angeles, 90095, California, USA

    Yang Yang

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Contributions

L.D. and J.You contributed equally to this work. L.D., J.You and Y.Y. developed the ideas. L.D. designed the chemical structure and performed materials synthesis and characterization. J.You fabricated the inverted tandem device and carried out data analysis. Y.H. and J.Yang participated in material synthesis and characterization. S.M. provided the ZnO for ICL. C.C. modified the PEDOT for ICL. T.M. and K.E. performed the certification at NREL. G.L. guided device testing at UCLA and coordinated certification. L.D., J.You, G.L. and Y.Y. prepared the manuscript. All authors discussed the results and commented on the manuscript. Y.Y. planned and supervised the project.

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Correspondence to Yang Yang.

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Dou, L., You, J., Yang, J. et al. Tandem polymer solar cells featuring a spectrally matched low-bandgap polymer. Nature Photon 6, 180–185 (2012). https://doi.org/10.1038/nphoton.2011.356

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