Hierarchical orientation of crystallinity by block-copolymer patterning and alignment in an electric field

Pola Goldberg Oppenheimer, Dinesh Kabra, Silvia Vignolini, Sven Hüttner, Michael Sommer, Katharina Neumann, Mukundan Thelakkat, Ullrich Steiner

Research output: Contribution to journalArticlepeer-review

22 Citations (Scopus)


Electron and hole conducting 10-nm-wide polymer morphologies hold great promise for organic electro-optical devices such as solar cells and light emitting diodes. The self-assembly of block-copolymers (BCPs) is often viewed as an efficient way to generate such materials. Here, a functional block copolymer that contains perylene bismide (PBI) side chains which can crystallize via π–π stacking to form an electron conducting microphase is patterned harnessing hierarchical electrohydrodynamic lithography (HEHL). HEHL film destabilization creates a hierarchical structure with three distinct length scales: (1) micrometer-sized polymer pillars, containing (2) a 10-nm BCP microphase morphology that is aligned perpendicular to the substrate surface and (3) on a molecular length scale (0.35–3 nm) PBI π–π-stacks traverse the HEHL-generated plugs in a continuous fashion. The good control over BCP and PBI alignment inside the generated vertical microstructures gives rise to liquid-crystal-like optical dichroism of the HEHL patterned films, and improves the electron conductivity across the film by 3 orders of magnitude.
Original languageEnglish
Pages (from-to)1063-1070
JournalChemistry of Materials
Issue number7
Early online date28 Mar 2013
Publication statusPublished - 9 Apr 2013


  • anisotropic optical behavior
  • electron-conducting block-co-polymer
  • hierarchical electrohydrodynamic patterning
  • orientation of crystallinity


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