Comparison of spin and charge transport in organic semiconductor P3HT

ORAL

Abstract

We have investigated spin and charge transport processes in regio-regular poly(3-hexylthiophene) (P3HT) in order to compare spin-transport and charge-transport in organic semiconductors. For the spin transport we measured the spin diffusion length, $\lambda_{s}$ via the inverse spin Hall effect (ISHE) in NiFe/P3HT/Pt trilayer devices, whereby a pure spin-current is generated in the polymer by spin-pumping from the ferromagnetic layer (NiFe), then diffuses to the Pt layer where it is converted into an electrical signal due to the strong spin-orbit coupling of Pt. For the charge transport we measured the carrier mobility of photogenerated charges via the time of flight technique. We also determined the (longitudinal) spin relaxation time, T$_{2}$ by pulsed EPR method, which allows us to calculate the spin diffusion coefficient D$_{s}$ from $\lambda_{s}$. Finally we relate D$_{s}$ to the charge diffusion coefficient D$_{c}$, which is determined from the charge mobility measurements.

*Supported by the NSF (DMR-1404634) and NSF-MRSEC (DMR-1121252)

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Authors

  • Matthew Groesbeck

    • Department of Physics & Astronomy, University of Utah

  • Haoliang Liu

    • Department of Physics and Astronomy, University of Utah
    • Department of Physics & Astronomy, University of Utah

  • Evan Lafalce

    • Univ of Utah
    • Department of Physics & Astronomy, University of Utah

  • Dali Sun

    • Univ of Utah
    • Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112, USA
    • Department of Physics & Astronomy, University of Utah

  • Hans Malissa

    • University of Utah
    • Department of Physics and Astronomy, University of Utah
    • Department of Physics & Astronomy, University of Utah

  • Marzieh Kavand

    • Department of Physics & Astronomy, University of Utah

  • C Boehme

    • Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112, USA
    • University of Utah
    • Department of Physics & Astronomy, University of Utah
    • Department of Physics and Astronomy, University of Utah, Salt Lake City, 84112, USA

  • Zeev Valy Vardeny

    • Univ of Utah
    • Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112, USA
    • University of Utah
    • Department of Physics & Astronomy, University of Utah