Uniform film of conjugated polymer for light-emitting device by electrophoretic deposition

This paper reports on the electrophoretic deposition from suspensions of a polyfluorene-based conjugated polymer with various good/poor solvent ratios. It has been found that the roughness of the film strongly depends on the good/poor solvent ratio of the parent suspension. That is, rough and turbid films are obtained when the concentration of the poor solvent is high, while uniform and transparent films, which are suitable for polymer devices, can be obtained without any post-deposition treatment in the case of low poor solvent content. Fabrication of a polymer light-emitting device using the conjugated polymer film has also been demonstrated.