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Tuning organic magnetoresistance in polymer-fullerene blends by controlling spin reaction pathways

Nature Communications volume 4, Article number: 2286 (2013) | Download Citation

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Abstract

Harnessing the spin degree of freedom in semiconductors is generally a challenging, yet rewarding task. In recent years, the large effect of a small magnetic field on the current in organic semiconductors has puzzled the young field of organic spintronics. Although the microscopic interaction mechanisms between spin-carrying particles in organic materials are well understood nowadays, there is no consensus as to which pairs of spin-carrying particles are actually influencing the current in such a drastic manner. Here we demonstrate that the spin-based particle reactions can be tuned in a blend of organic materials, and microscopic mechanisms are identified using magnetoresistance lineshapes and voltage dependencies as fingerprints. We find that different mechanisms can dominate, depending on the exact materials choice, morphology and operating conditions. Our improved understanding will contribute to the future control of magnetic field effects in organic semiconductors.

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Acknowledgements

This work was supported by the Dutch Technology Foundation STW via the NWO VICI-grant ‘Spin Engineering in Molecular Devices’ (Project No. 06628) and NWO-NANO grant ‘Chasing the spin in organic spintronics’ (Project No. 11424).

Author information

Affiliations

  1. Department of Applied Physics, Center for NanoMaterials (cNM), Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands

    • P. Janssen
    • , M. Cox
    • , S.H.W. Wouters
    •  & B. Koopmans
  2. Molecular Materials and Nano Systems, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands

    • M. Kemerink
    •  & M.M. Wienk

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Contributions

P.J. and M.C. contributed equally to the present work. P.J. and M.C. carried out the experiments and analysed the data. P.J. and S.H.W.W. carried out the experiments on the SY-PPV polymer. M.K. provided expertise on organic device modelling and M.C. performed the simulations. M.M.W. assisted in sample preparation. B.K. supervised the project. P.J., M.C. and B.K. wrote the manuscript. All authors discussed the results and manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to B. Koopmans.

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    Supplementary Figures S1-S5, Supplementary Tables S1-S2, Supplementary Notes 1-3

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DOI

https://doi.org/10.1038/ncomms3286

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