title: Assembling semiconducting molecules by covalent attachment to a lamellar crystalline polymer substrate.
abstract: We have investigated the potential of polymers containing precisely spaced side-branches for thin film applications, particularly in the context of organic electronics. Upon crystallization, the side-branches were excluded from the crystalline core of a lamellar crystal. Thus, the surfaces of these crystals were covered by side-branches. By using carboxyl groups as side-branches, which allow for chemical reactions, we could functionalize the crystal with semiconducting molecules. Here, we compare properties of crystals differing in size: small nanocrystals and large single crystals. By assembling nanocrystals on a Langmuir trough, large areas could be covered by monolayers consisting of randomly arranged nanocrystals. Alternatively, we used a method based on local supersaturation to grow large area single crystals of the precisely side-branched polymer from solution. Attachment of the semiconducting molecules to the lamellar surface of large single crystals was possible, however, only after an appropriate annealing procedure. As a function of the duration of the grafting process, the morphology of the resulting layer of semiconducting molecules changed from patchy to compact.
authors.affiliation: Institute of Physics, University of Freiburg, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany.
authors.forename: Rainhard
authors.initials: R
authors.lastname: Machatschek
authors.affiliation: Chair of Chemical Materials Science, Department of Chemistry, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: Ortmann
authors.affiliation: Institute of Physics, University of Freiburg, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany.
authors.forename: Renate
authors.initials: R
authors.lastname: Reiter
authors.affiliation: Chair of Chemical Materials Science, Department of Chemistry, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Mecking
authors.affiliation: Institute of Physics, University of Freiburg, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany.
authors.forename: Günter
authors.initials: G
authors.lastname: Reiter
keywords: monolayer; nanocrystals; precision polyethylene; semiconducting molecules; single crystals