The morphological, structural, and electrical properties of poly(3-methylthiophene) polymer brush films grown on indium tin oxide up to 120 nm thick are characterized. Optical and X-ray spectroscopy experiments indicate that the polymer chains have a nearly isotropic average orientation at low (&lt; 10 nm) and high (&gt; 30 nm) thicknesses, with vertical anisotropy in between. Atomic force microscopy shows that the film surfaces consist of column-shaped domains with an average cross-sectional area and density that are independent of film thickness. Au electrodes were printed onto the polymer brush films, giving a measured bulk resistivity along the columns of 1.4 × 10<sup>5</sup> Ω*cm, two orders of magnitude lower than typical values for spuncast poly(3-alkylthiophene) films. The resistance along individual polymer chains in the columns is estimated to be 360 GΩ/nm per molecule, comparable to molecular wires that exhibit charge transport by intramolecular processes. The enhanced conduction is likely due to additional intramolecular transport pathways enabled by the electrode-polymer brush-electrode device architecture, establishing conjugated polymer brushes as a platform for studying the interplay between synthesis, morphology, and charge transport phenomena.

Morphology, structure, and enhanced intramolecular conduction in ultralong conjugated polymer brushes

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.