Beilstein Journal of Nanotechnology (Jun 2016)

Assembling semiconducting molecules by covalent attachment to a lamellar crystalline polymer substrate

  • Rainhard Machatschek,
  • Patrick Ortmann,
  • Renate Reiter,
  • Stefan Mecking,
  • Günter Reiter

DOI
https://doi.org/10.3762/bjnano.7.70
Journal volume & issue
Vol. 7, no. 1
pp. 784 – 798

Abstract

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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.

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