The Preparation Of ZnO Micro-nano Hollow Structure Films On The Modified Si Substrate By Hydrothermal Method

As a typical wide band gap metal oxide semiconductor of ?-? group, Zinc oxide (ZnO) is one of the most widely researched semiconductors in recent years. The 3.4eV wide band gap of ZnO leads to its excellent shortwave light emitting ability, and the large exciton binding energy of 60meV makes it the most promising blue-ultraviolet emitting material at room temperature.Besides the photoelectric capability, many other excellent properties, like gas sensitivity, transparent conductivity and piezoelectricity make it favorable in every correlative field.From the micro perspective, ZnO has a variety of nanostructures. For example, nanowires, nanorods, nanotubes, nano-rings, nanosheets, nano-flowers and so on. All of these structures, especially the hollow structure is the most desired one. Not only because it has excellent optical, electrical, thermal and mechanical performance, but also because of the porous and a large surface area, which make it gained a wide application. From the macro perspective, in the research and application of ZnO, the thin film is the main form of struction. With micro-nano structures, ZnO thin films has become the focus of materials research, due to the quantum size effect, surface effect and its unique physical and chemical properties, which are different from the conventional materials.However, ZnO films that mostly composed of the micro-nano scale solid particles perform worse than that composed of hollow structure which has the porous and a large surface area. Besides, the former has a c-axis preferred orientation, which is somewhat restricted in some fields.Based on the current problems, we analyzed the relationship between micro-nano structure arrays and thin films by using a new idea to prepare the ZnO thin films, which has a a-axis preferred orientation. Starting from experiment, using the modified silicon(110) as growth substrate, with a new hydrothermal microemulsion method, highly oriented ZnO micro-nano hollow structure arrays have been prepared on the "V" grooved substrate.So, ZnO thin films of micro-nano hollow structure with a-axis preferred orientation can be obtained by this method.We used wet etching technique to modify the silicon(100) substrate and optimized the cleaning of photoresist and the placement of substrate during etching process. Finally, we got a better shaped V-groove to provide a good substrate material for the next step.We used a new microemulsion hydrothermal method to prepare the ZnO micro-nano hollow structure on the Si substrate, and worked out the best experimental conditions for hydrothermal growth. On the basis of the experiment, the growth mechanism of micro-nano hollow structure of ZnO was discussed in detail.We prepared the ZnO seed layer with V-groove etched substrates, which was then treated with continuous hydrothermal deposits ten times to obtain neatly arranged ZnO micro-nano tube arrays. Ultimately, the ZnO micro-nano hollow structured films with a-axis preferred orientation on the V-groove etched substrates was successfully prepared.