Electrophoretic deposition of nanostructured film from colloidal suspensions of conjugated polymers

The preparation of colloidal suspension through a simple method, injection of a small amount of toluene solution of target materials into non-solvent acetonitrile, has been successfully demonstrated for various conjugated polymers such as poly(3-octadecylthiophene), PAT-18. a poly(9,9-dioctylfluorenyl-2,7-yleneethynylene), POFE and poly(2-methoxy-5-(2’-ethylhexyloxy)- 1,4-phenylene vinylene), MEH-PPV and fullerene, C60. The colloidal suspension of mixtures of MEH-PPV and C60 with almost equivalent weight ratio has also been obtained through the same process. The electrophoretic deposition from these suspensions results in nanostructured polymer film, as indicated by the atomic force microscopy (AFM) observation. A simple recipe for controlling average size of the colloidal particles in the nanostructured POFE , which involves changing the nonsolvent: solvent ratios, may be useful for controlling the nanoporosity of the film, which is very important in optoelectronic, electronic and electrochemical application. We report a novel way to laod large amounts of unmodified C60 into the conjugated polymer, MEH-PPV. Since the polymer films obtained through this process has worked as emission layer in a light-emitting device, the film obtained through this process will also be able to work in photocells.