The Preparation And Photoelectric Properties Of One Dimensional ZnO Arrays And ZnO/TiO₂ Core-Shell Structure Electrode

The emergence of a large number of extreme weather events (such as fog and haze), has become increasingly prominent environmental problems of the greenhouse effect, and so has been made on human life a great deal of respiratory diseases increasing, which makes people think about how to use more energy efficient, more environmentally friendly materials to develop new sources of energy while developing industrial economy. So the solar power attracted the sight of people. Studies also have shown that worldwide energy consumption is only the energy of the sun illuminating the earth for forty-five minutes.Up to now, the use of solar power is mainly two types, i.e. solar power and photovoltaic conversion. Silicon-based thin-film batteries and dye-sensitized solar cells are more researched. The core of the dye-sensitized solar cell is the nanoporous semiconductor thin film, and TiO2 and ZnO thin films are the study hotpots. ZnO and TiO2 have the similar band gap and the electronic transmission loop, which means ZnO is a potential alternative to the application of TiO2 semiconductor materials in the field of DSCC.In this paper, the sol-gel method was used to prepare ZnO seed crystals on FTO conductive glass substrate. Hydrothermal growing in a certain concentration of the aqueous solution to form ZnO micro/submicron rod arrays based on the seed crystal was studied. The aspect ratio of ZnO arrays was controlled by varying the experimental conditions. And then ZnO nanoarray was wrapped by a layer of TiO2 crystals assisted with vacuum. One dimension ZnO arrays/TiO2 core-shell composited structure can improve the photoelectric conversion efficiency of ZnO submicron rod arrays film. The effect of composition of sol, the pulling-coating speed, the concentration of hydrothermal precursor solution and material types of Zinc on the seed layer and ZnO arrays were researched. The obtained results are as follows.ZnO crystals with hexagonal crystal structure and different morphologies were obtained using different raw materials and reaction conditions. The experimental results show that the orderly grown ZnO sub-micron rods can be formation when the mole ratio of zinc acetate and diethanolamine (DEA) in sol is 1:1, the pulling speed is 2 mm/s and the hydrothermal precursor solution concentration of zinc acetate and hexamethylene tetramine (HMT) is 25mM.Aspect ratio of ZnO submicron rods can be controlled by adding polyethylen-eimine (PEI) and changing the hydrothermally grown number. ZnO submicron rod arrays with approximate 10μm thick was immersed into TiO2 sols in vacuum and wrapped a layer of TiO2 crystals after calcined at a certain temperature. The formation of one-dimensional ZnO/TiO2 core-shell composite structure increased the specific surface area of the ZnO array thin film, enhanced the adsorbility of ZnO arrays. Thus, the fill factor and photoelectric conversion efficiency were increased.