Challenges found when patterning semiconducting polymers with electric fields for organic solar cell applications

摘要

A material-independent, contactless structuring method of semiconducting organic materials for the fabrication of interface-enhanced bilayer solar cells is not available so far. Patterning of thin films using electrohydrodynamic instabilities possesses many desired characteristics and has convincingly been used as a simple method to structure and replicate patterns of nonconducting polymers on submicrometer length scales. However, the applicability of this technique to a wider range of materials has not been demonstrated yet. Here, we report attempts to structure poly(p-phenylene vinylene) in a similar way. We found that thin films of poly(2-methoxy-5-(2 ′ -ethylhexyl-oxy)-1,4- phenylene-vinylene) (MEH-PPV) and poly(2-methoxy-5-(3 ′, 7 ′ -dimethyloctyloxy)-1,4-phenylene-vinylene) (MDMO-PPV) could not be destabilized at all in the limited accessible range of the experimental parameters set by the delicate chemical nature of these materials. We discuss failure origins and present possible loopholes for the patterning of semiconducting polymers using electric fields.