High density array of CdS nanoporous films on ITO from self-assembly of block copolymer

Among many methods to prepare nanoporous structure in inorganic films, block copolymers have been widely employed. In this work, we have systematically studied the orientation of the cylindrical PS microdomains in polystyrene-b-polymethyl methacrylate (PS-b-PMMA) block copolymer thin films on a conducting ITO substrate and obtained perfect vertically orientated PS cylinders by modifying the substrate. Furthermore, the well-ordered morphology of the block copolymer thin film has been used successfully as a template to prepare nanoporous semicon CdS thin film with hexagonal crystalline phase. The facile and effective approach would be universal and open new avenues for fabrication of some nanomaterials.