Goldberg-Oppenheimer, P and Kabra, D and Vignolini, S and Hüttner, S and Sommer, M and Neumann, K and Thelakkat, M and Steiner, U (2013) Hierarchical orientation of crystallinity by block-copolymer patterning and alignment in an electric field. Chemistry of Materials, 25. pp. 1063-1070. ISSN 0897-4756Full text not available from this repository.
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. © 2013 American Chemical Society.
|Uncontrolled Keywords:||anisotropic optical behavior electron-conducting block-co-polymer hierarchical electrohydrodynamic patterning orientation of crystallinity|
|Depositing User:||Cron job|
|Date Deposited:||04 Feb 2015 22:43|
|Last Modified:||01 May 2015 18:26|