Theoretical Studies Of Si-OH And SiO₂ Structures On Silicon And Porous Silicon Surface

Si-OH and SiO₂ which exist on silicon and its compound material surface have prodigious influence on the capacity of silicon and its compound materials. For example, Si-OH which exists on porous silicon surface has significant meaning on porous silicon s luminescence , surface adsorption and explosion. In silicon apparatus, SiO₂ film which lies on silicon surface affects the aggradation of membrane on silicon superficial, and affects the capacity of silicon apparatus. The physical chemistry properties of one substance is determined by its surface microstructure. So, the study of surface structure form, microstructure, element, surface bond of silicon and its compound material has much importance on the continual study of surface chemical state and surface physical chemistry adsorption, and can accelerate the betterment manufacture of silicon apparatus.Because of micromechanism and electrical capacity, the method of the directness observation on silicon and its compound material s surface structure has been confined. Cyber-simulation can meterage the quantities which can not be measured by experiment straightly, and makeup the shortage of the experimental research. Thus, it is a important way to use exoterica means to study silicon and its compound material. In this paper, we take CASTEP formality which calculates on first principle calculation to study Si-OH and SiO₂ structures on silicon and porous silicon surface particularly. First of all, the plane-wave pseudopotential method within the local-density approximation(LDA) and generalized gradient approximation(GGA) was used to investigate the structures of Si-OH and SiO₂ on silicon surface.After analysizing the results, we concluded that GGA is more suitable in silicon substance theoretical calculation. In the basis of that conclusion, plane waves using ultrasoft pseudo-potential technique based on density functional theory was used to calculate Si-OH structures on porous silicon surface and Si/SiO₂ interficial structures. The results show the character of Si-OH structures which lies...