Research Of The Fabrication Of Si/ZnO Micro-nano Hierarchical Structure For Photoanode

Solar energy is a kind of clean, renewable energy. Through the preparation of photoelectrochemical solar cells based on micro-nano structures, a similar nature photoelectrochemical process of photosynthesis can be achieved, which use sunlight to split water to get hydrogen. Solar energy is stored in the hydrogen to obtain hydrogen energy which can be stored and transported easily. This has great application prospects. In photoelectrochemical solar cell manufacturing, the key is the micro-nano structure design and manufacturing of its photoelectrode. Focusing on this point and combining the demand of the Excellent Youth Science Fund Project "Bionic micro-nano manufacturing and applied research" and the National Natural Science Foundation of China "Controlled bionic design and preparation of the dye-sensitized solar cell photoanode structure", the article propose to use Si/ZnO hierarchical structure as photoelectrochemical solar cell photoelectrode. The concrete work is carried out as follows:1, Research on the preparation of Si/ZnO nano/nano hierarchical structure and its application on photoelectrochemical hydrogen generation. Metal assisted chemical etching process and hydrothermal growth process are studied. Si nanowire arrays and ZnO nanowire arrays are fabricated on Si substrates. The detailed mechanism of metal assisted chemical etching and its process are studied. The Si/ZnO nano/nano hierarchical structure is fabricated based on the above two processes and further characterization is carried out. The packaging process of the photoelectode based on micro-nano structures of the photoelectrochemical solar cells is investigated and its working mechanism is analyzed. A photoelectrochemical solar cell performance test platform is built. The Si/ZnO nano/nano hierarchical structure is packaged as the photoelectrochemical solar photoelectrode and its performance for photoelectrochemical hydrogen generation is analyzed. The experimental results show that the photocurrent of the hierarchical structure has been significantly improved compared with the ZnO nanowire arrays grown on flat Si substrate.2, Research on the preparation of Si/ZnO micro/nano hierarchical structure and its application on photoelectrochemical hydrogen generation. A platform for the growth of Si microwire arrays with CVD process is built, including the gas source, gas transmission systems, high-temperature process chamber, vacuum and exhaust treatment device, to study the CVD-VLS growth process for the Si microwire arrays. Based on the hydrothermal growth process and CVD-VLS growth process, the Si/ZnO micro/nano hierarchical structure is fabricated packaged as the photoelectrochemical photoelectrode. Test of its photoelectrochemical hydrogen generation performance is carried. The experimental results show that the hierarchical structure has better photocatalytic properties.3, Research on the preparation of composite Si/ZnO micro/nano hierarchical structure and its application on photoelectrochemical hydrogen generation. For the low absorption efficiency and light corrosion of the Si/ZnO micro/nano hierarchical structure, further modification is carried out, i.e. the narrow bandgap semiconductor material CdS and CdSe film are used to increase the light absorption and IrOx nanoparticales are used too. On the other hand, after modification, the composite structure is a kind of two levels of core-shell structure. It also helps photoelectrochemical performance boost. The photocurrent of the hierarchical structure after modification is significantly improved and the light corrosion is resolved which exhibited very good photochemical stability during the long light.