Chaoyang Li
Kochi University of Technology, 782-8502, JAPAN
Title: Synthesis of metal oxide nanostructures for energy applications
Biography
Biography: Chaoyang Li
Abstract
Recently, more and more attention has been paid to the ZnO nanostructures for its potential applications such as gas sensor, UV laser, light emitting diode, dye-sensitized solar cell (DSSC), etc . Among these applications, ZnO based DSSC has been extensively investigated because ZnO exhibit similar bandgap with TiO2, however, ZnO is much easier to fabricate into nanostructures to enlarge the surface area and has much higher electron mobility. Many methods have been developed for synthesizing ZnO nanostructures including chemical vapor deposition, hydrothermal method, sol-gel method and chemical bath deposition, etc. We had succeeded in developing a novel multiple-annealing method,which includes both the reducing reaction and oxidazation reaction processes, to synthesize ZnO nanostructures on different transparent conductive oxide films at a low temperature. It was found that the substrates had significantly influence on vertical alignment of ZnO nanostructures. The lower mismatch of the lattice imperfection between ZnO film and substrates contributed to fabricating ZnO film with good crystallinity and well-aligned ZnO nanostructures. The annealing temperature contributed to the density and length of ZnO nanostructures. The surface morphology and the crystallinity of the ZnO nanostructures could be modified by a novel mistCVD method. In order to increase the convertion efficiency of DSSC, a designed photoanodes using vertically aligned ZnO nanostructures were applied to replace nanocrystalline porous TiO2 films. The pure anatase-structured- TiO2 thin film was successfully coated on ZnO nanostructures to improve the stablity by mist CVD method. As the result, the conversion efficiency of DSSC was significantly improved.