Adsorption and desorption behavior of CO on S passivated 4H-SiC by electric field

2017 International Conference on Materials and Intelligent Manufacturing

材料科学;机械制造

Yan, Zhengxin^1 ; Hou, Anhong^1 ; Wang, Yongsheng^1 ; Zhang, Shaohua^1

College of Science, Xi'An University of Science and Technology, Xi'an, China^1

关键词: Adsorption and desorptions;    Adsorption energies;    Atom adsorption;    Density of state;    Desorption behavior;    Partial density of state;    Positively charged;    S adsorptions;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/244/1/012014/pdf
DOI  :  10.1088/1757-899X/244/1/012014

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Adsorption energy and partial density of states of S at three typical positions on 4H-SiC (001) surface were calculated which based on the density functional theory (DFT).The results show that S adsorption is the most stable in the bridge position and unstable in the hollow. The density of states near the Fermi level can be effectively reduced by using the S atom on the surface of 4H-SiC. The adsorption and desorption of CO on the surface of S passivated 4H-SiC at different applied electric fields were calculated by selecting hollow of S atom adsorption. It turned out that the positive electric field is not conducive to the adsorption of CO and the reverse is favorable for adsorption, but when the forward electric field F is greater than 2eV/Å/e the desorption behavior of S atom is more obvious. Because of the S atom is positively charged which made the Si-C bond length increases rapidly under the action of electric field.