Simple and rapid fabrication of large-area 2D colloidal crystals for nanopatterning of conducting polymers

Abstract

Here we demonstrate a versatile and simple method for the rapid fabrication of two-dimensional (2D) colloidal crystals as the template for nanopatterning of conducting polymer. Our method involves the electrophoretic deposition of negatively-charged colloidal particles on an indium tin oxide (ITO) electrode and the formation of 2D colloidal crystals at the air-water interface by the dipping of the colloidal assembly on the electrode. On the dipping step, the particles were spread from the electrode and self-assembled into the hexagonally close-packed 2D colloidal crystals floating at the air-water interface. The obtained colloidal crystals could be transferred to various substrates and stacked into three-dimensional (3D) colloidal crystals of the controlled number of layers by simply repeating the transfer procedure. Based on the proposed technique, the fabrication of 2D colloidal crystal patterns by a soft lithographic technique and the fabrication of nanostructured conducting polymers with a template using the prepared 2D colloidal crystals were demonstrated. The proposed method does not require complicated equipment or the precise control of experimental conditions, which is expected to be useful in the nanostructure fabrication.