We report the structural evolution of diamond films in a plasma assisted hot filament chemical vapour deposition system with a variable substrate bias through a two-step process including deposition and subsequent modification. It is found that the diamond surfaces can be significantly modified after the treatment of hydrogen plasma. The surfaces with pyramidic structures form under the proper treated duration and temperature with a decrease in the content of amorphous carbon. As the treatment is prolonged, the surface presents ellipsoid structures while the diamond film becomes amorphous. Furthermore, 50 µm-long columns appear instead of the ellipsoids in a higher regime of the substrate temperature. These results suggest that the hydrogen plasma treatment and substrate temperature can significantly tune the surface topography of diamond films, and even give rise to chemical bonding variations with pronounced surface structures.
SiO 2 photonic crystal were successfully prepared by vertical deposition and then used as a template to fabricate SiO 2 -ZnO composite photonic crystals on ITO substrates by electrodeposition and subsequent calcination. A number of different deposition times were used. The morphologies of the silica opals and SiO 2 -ZnO composite photonic crystals were investigated by scanning electron microscopy. It was found that ZnO particles grew randomly on the surfaces of the silica spheres when the deposition time was short. As the deposition time was increased, the ZnO particles grew evenly on the surfaces of the silica spheres so that the interstitial space of the silica template was filled with ZnO particles. Reflectance spectra of the SiO 2 -ZnO composite crystals revealed that all of the fabricated photonic crystals exhibit a photonic band gap in the normal direction. [7]. However, the fabrication of 3-D opal photonic crystals is still a technical challenge, because many kinds of intrinsic defects such as plane defects, line defects, and dot defects appear during self-assembly. During self-assembly, surface charge *Corresponding author (email: fengbx@lzu.edu.cn) on colloidal spheres is a key element in successfully producing high quality colloidal crystals. Some scientists had fabricated SiO 2 photonic crystals with high quality by enhancing surface charge on SiO 2 spheres via modification with succinic acid [8]. In this work, vertical deposition was chosen as the self-assembly method to fabricate SiO 2 photonic crystal templates as it provides a relatively simple approach to obtaining high quality opal films.Silica or polymer opals do not have a full band gap because of their low refractive index (1.47 for silica). However, these opals are calculated to have a photonic band gap in the (111) direction, so opal-based materials, such as composite photonic crystals with different fillings and inverted opals [9][10][11], are of interest. ZnO is an important semiconductor material with a wide electronic band gap, which has a higher refractive index (2.1) than other materials. As a result, an increasing number of SiO 2 -ZnO composite photonic crystals have been fabricated by a range of methods [12,13].In this work, SiO 2 -ZnO composite photonic crystals were fabricated by electrodeposition followed by calcination at
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