Manipulation of discrete porphyrin–fullerene nanopillar arrays regulated by the phase separated infiltration of polymer in ternary blended organic thin-films.

Fabrication of nanostructure in various typed solar cell is of great importance in terms of the improvement of charge carrier collection and junction area. Here, we report that well-aligned nanopillar arrays are spontaneously developed in the process of the spin coating when a polymer is added to specific porphyrin–fullerene complexes. The nanopillars embedded in the polymers are composed of donor–acceptor assembled systems, based on J-type aggregation of a low-molecular zinc porphyrin derivative and subsequent integration of pyridylated fullerene derivative with coordination and orientation. The diameter and the height of the nanopillars can be controlled by the side chain-length and the concentration of the polymer as well as drying time after the spin coating. Structural, optical, and electrical properties of the nanopillar are also investigated. Finally, improved power conversion efficiency in the porphyrin–fullerene nanopillar is experimentally observed compared to that of the planar thin film prepared under similar conditions. [ABSTRACT FROM AUTHOR]