title: 2D coherent charge transport in highly ordered conducting polymers doped by solid state diffusion.
abstract: Doping is one of the most important methods to control charge carrier concentration in semiconductors. Ideally, the introduction of dopants should not perturb the ordered microstructure of the semiconducting host. In some systems, such as modulation-doped inorganic semiconductors or molecular charge transfer crystals, this can be achieved by spatially separating the dopants from the charge transport pathways. However, in conducting polymers, dopants tend to be randomly distributed within the conjugated polymer, and as a result the transport properties are strongly affected by the resulting structural and electronic disorder. Here, we show that in the highly ordered lamellar microstructure of a regioregular thiophene-based conjugated polymer, a small-molecule p-type dopant can be incorporated by solid state diffusion into the layers of solubilizing side chains without disrupting the conjugated layers. In contrast to more disordered systems, this allows us to observe coherent, free-electron-like charge transport properties, including a nearly ideal Hall effect in a wide temperature range, a positive magnetoconductance due to weak localization and the Pauli paramagnetic spin susceptibility.
authors.affiliation: Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, UK.
authors.forename: Keehoon
authors.initials: K
authors.lastname: Kang
authors.affiliation: Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, UK.|Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8561, Chiba, Japan.|JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Shun
authors.initials: S
authors.lastname: Watanabe
authors.affiliation: Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, UK.
authors.forename: Katharina
authors.initials: K
authors.lastname: Broch
authors.affiliation: Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg, Switzerland.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Sepe
authors.affiliation: Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, UK.
authors.forename: Adam
authors.identifier: 0000-0001-7232-7051
authors.initials: A
authors.lastname: Brown
authors.affiliation: Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, UK.
authors.forename: Iyad
authors.initials: I
authors.lastname: Nasrallah
authors.affiliation: Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Nikolka
authors.affiliation: Department of Chemistry and Centre for Plastic Electronics, Imperial College, London SW7 2AZ, UK.
authors.forename: Zhuping
authors.initials: Z
authors.lastname: Fei
authors.affiliation: Department of Chemistry and Centre for Plastic Electronics, Imperial College, London SW7 2AZ, UK.
authors.forename: Martin
authors.identifier: 0000-0001-6879-5020
authors.initials: M
authors.lastname: Heeney
authors.affiliation: Division of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Matsumoto
authors.affiliation: Division of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan.|Tsukuba Research Center for Interdisciplinary Materials Science (TIMS), University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Marumoto
authors.affiliation: Department of Applied Physics, Nagoya University, Chikusa, Nagoya 464-8603, Japan.
authors.forename: Hisaaki
authors.initials: H
authors.lastname: Tanaka
authors.affiliation: Department of Applied Physics, Nagoya University, Chikusa, Nagoya 464-8603, Japan.
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Kuroda
authors.affiliation: Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, UK.
authors.forename: Henning
authors.initials: H
authors.lastname: Sirringhaus