Hierarchical Orientation of Crystallinity by Block-Copolymer Patterning and Alignment in an Electric Field
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- 作者：Pola Goldberg-Oppenheimer ; Dinesh Kabra ; Silvia Vignolini ; Sven H眉ttner ; Michael Sommer ; Katharina Neumann ; Mukundan Thelakkat ; Ullrich Steiner
- 刊名：Chemistry of Materials
- 出版年：2013
- 出版时间：April 9, 2013
- 年：2013
- 卷：25
- 期：7
- 页码：1063-1070
- 全文大小：606K
- 年卷期：v.25,no.7(April 9, 2013)
- ISSN：1520-5002
文摘
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 蟺鈥撓€ 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鈥? nm) PBI 蟺鈥撓€-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.