Fabrication of ZnO colloidal photonic crystal by spin-coating method

We describe a simple and effective method, based on spin coating, developed for the fabrication by self-assembly of ZnO colloidal photonic crystal structures. The scanning electron microscope images indicate ordered structures with few defects. All the ordered structures exhibit a stop band in optical transmission experiments. The position of the stop band scales nicely with the particles size, indicating that it is an intrinsic feature of the photonic crystals. With decrease of ZnO particles size, the positions of the band are shifted to the shorter wavelength.