Surface Defects And Surface Modification Of Silicon Carbide Nanowires

Silicon carbide(SiC),as the third-generation semiconductor material of typical wide band gap,has attracted great attention due to its good performance in high frequency,high temperature,radiation and extreme environment.In the preparation process of nano meterials,due to the experimental conditions and the influence of the environment,many vacancies and other intrinsic defects are unavoidable,and these defects have a great influence on the properties of the material.Surface modification as a method of not altering the inherent properties of the material which could suppressed the influence of surface defects on the nanowires.In this paper,we systematically studied the vacancy defects on 2H-SiC and the effect of both hydrogen passivation and hydroxyl passivation methods impact on 2H and3C-SiC.The main contents are as follows:Firstly,the research background,structure and basic properties of silicon carbide nanowires are introduced,and the basic principles are described.Then,we analyzed the electron structure and optical properties of 2h-sic with vacancy defects,and found that the influence of two different vacancy defects on the photoelectric properties of carbon atom and silicon atom was significant.In the end,we performed two kinds of surface modification calculations on hydrogen passivation and hydroxyl passivation of 2H-SiC and 3C-SiC,and found that after passivation,there was a significant difference between energy band and dielectric constant and other electrical properties compared with that of unpassivation,and then analyzed the reasons for this situation from the state density.