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Solution-based electrical doping of semiconducting polymer films over a limited depth

Nature Materials volume 16, pages 474–480 (2017)Cite this article

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Abstract

Solution-based electrical doping protocols may allow more versatility in the design of organic electronic devices; yet, controlling the diffusion of dopants in organic semiconductors and their stability has proven challenging. Here we present a solution-based approach for electrical p-doping of films of donor conjugated organic semiconductors and their blends with acceptors over a limited depth with a decay constant of 10–20 nm by post-process immersion into a polyoxometalate solution (phosphomolybdic acid, PMA) in nitromethane. PMA-doped films show increased electrical conductivity and work function, reduced solubility in the processing solvent, and improved photo-oxidative stability in air. This approach is applicable to a variety of organic semiconductors used in photovoltaics and field-effect transistors. PMA doping over a limited depth of bulk heterojunction polymeric films, in which amine-containing polymers were mixed in the solution used for film formation, enables single-layer organic photovoltaic devices, processed at room temperature, with power conversion efficiencies up to 5.9 ± 0.2% and stable performance on shelf-lifetime studies at 60 °C for at least 280 h.

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Figure 1: Optical properties of P3HT films immersed in a solution of PMA.
Figure 2: Properties and interactions of doped P3HT films.
Figure 3: Photo-oxidation and electrical properties of doped P3HT films.
Figure 4: PMA-doped OPV devices.
Figure 5: Single-layer OPV devices.

Change history

  • 10 January 2017

    In the original version published, the S(2s) peak in Fig. 2a was not clearly labelled. This has now been corrected.

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Acknowledgements

This work was funded in part by the Department of the Navy, Office of Naval Research Award No. N00014-14-1-0580 and N00014-16-1-2520, through the MURI Center CAOP, Office of Naval Research Award N00014-04-1-0313 and by the Department of Energy through the Bay Area Photovoltaic Consortium under Award Number DE-EE0004946. The authors would also like to thank J. Anthony and S. Barlow for helpful discussions. B.K. acknowledges a Visiting Professorship from the University of Cologne, Germany.

Author information

Authors and Affiliations

  1. Center for Organic Photonics and Electronics (COPE), School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA

    Vladimir A. Kolesov, Canek Fuentes-Hernandez, Wen-Fang Chou, Felipe A. Larrain, Sangmoo Choi & Bernard Kippelen

  2. INAMORI Frontier Research Center, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan

    Naoya Aizawa

  3. Center for Polymers and Organic Solids, University of California, Santa Barbara, California 93106, USA

    Ming Wang, Guillermo C. Bazan & Thuc-Quyen Nguyen

  4. Department of Applied Physics, Eindhoven University of Technology, Box 513, 5600 MB Eindhoven, Netherlands

    Alberto Perrotta

  5. Center for Organic Photonics and Electronics (COPE), School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA

    Samuel Graham

  6. Center for Organic Photonics and Electronics (COPE), School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, USA

    Seth R. Marder

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  1. Vladimir A. Kolesov
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Contributions

V.A.K., C.F.-H., N.A., S.R.M., W.-F.C., F.A.L. and B.K. conceived and developed the ideas. V.A.K. and F.A.L. designed the experiments and performed device fabrication, electrical characterization. A.P., C.F.-H. and S.G. performed shelf lifetime and thermal stress experiments. C.F.-H. and W.-F.C. performed photo-oxidation and spectroscopic ellipsometry experiments. C.F.-H. modelled spectroscopic ellipsometry data. S.C. and W.-F.C. performed XPS measurements. M.W., G.C.B. and T.-Q.N. synthesized the donor polymer PIPCP used in this study. C.F.-H., S.R.M. and B.K. coordinated and directed the study. All authors contributed to the manuscript preparation.

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Correspondence to Bernard Kippelen.

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Kolesov, V., Fuentes-Hernandez, C., Chou, WF. et al. Solution-based electrical doping of semiconducting polymer films over a limited depth. Nature Mater 16, 474–480 (2017). https://doi.org/10.1038/nmat4818

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