The Theoretical Research Of The Effects Of Vacancy And Doping On Electronic Structure Of ZnO Nanowires

Zinc Oxide(ZnO) is of great potential as a typical semiconductor, especially the properties of wide bandgap and high excition binding energy, stimulating the research enthusiasm of people greatly. While ZnO nanowires grasp more attentions because of its advantages being a nanometer materials. However, there is still problem for the applications in the field of photo-electricity, since it is proved being a n-type material. In the paper, we investigate the one-dimensional ZnO nanowires with two different sections using the first principle calculation based on density functional theory. And discuss the effects of vacancy and doping on the physical properties employing the module of DMol3, respectively. The main research contents are as follows:Firstly, this thesis represents the research background of nanometer materials, the classification and the preparation method simply. The performance and application of ZnO nanomaterials are introduced daily and industrially, and the research significance and purpose of this paper are put forward, too.Secondly, the paper studies the effects of size and oxygen vacancy concentration of hexagonal ZnO nanowires on the structural stability, bond length, bond angle,electronic structure, comparatively. It is described how the concentration of surface zinc atoms and the body oxygen atoms influence the conduction-band bottom and the valence-band top, respectively, and the change rule of band gap along the size.Finally, it is considered how the size and the doping concentration of trigonal one-dimensional ZnO nanowires influence its physical properties, realizing the simulation of the stability, the band structure and density of states and the p-type doping. In addition, the scattering mechanism of undoping ZnO nanowires is researched and the law of migration rate along with the change of temperature and the size of the structure are analyzed.