甲烷在多孔硅表面物理吸附特征研究(英文)  

Study on physical adsorption mechanism of methane on the porous Si surface

作　　者：闫东芝[1] 炎正馨[1] 龚安[1] 陈倩[1] 廖谦[1] 

机构地区：[1]西安科技大学理学院,西安710054

出　　处：《原子与分子物理学报》2014年第4期555-559,共5页Journal of Atomic and Molecular Physics

基　　金：中国博士后特别资助(201003678);陕西省教育厅科学专项基金项目(12JK0965)

摘　　要：在密度泛函理论耦合超软贋势第一性原理的平台上,研究了甲烷在Si(111)表面的物理吸附特性.通过建立硅晶胞的不同吸附位置(top、bridge、fcc)模型,对比分析了甲烷在相应位置吸附界面变化的键结构、吸附能和态密度,获得了相应吸附点的吸附特征.对比分析的结果表明,甲烷只有在fcc位置物理吸附状态较为理想.分析态密度、键长及键角等数据揭示fcc位甲烷吸附对体系硅晶胞有很大的影响,其体系的键能最低,即此时体系结构最稳定.本文所得研究成果可用于Si表面对甲烷气体的敏感性分析及气体传感器领域.The physical adsorption behavior of methane on Si （111）surface was investigated using first-principles calculations based on density-functional theory and ultrasoft pseudopotentials.To compara-tively analyze the adsorbing characteristics of methane,different adsorbing positions of Si （111）surface had been structured to figure out the more optimal absorbing position.In the paper,we set up three dif-ferent positions （top,bridge,fcc）of the adsorbing model.The interface structures changes were evi-denced by the bond structure,adsorption energy and density of states.The adsorption energy of meth-ane shows the fcc position is a favorite point for physical adsorption on Si （1 1 1 ）surface.The data of density of states and bond structure clearly reveal that methane adsorbed on the fcc position of Si （111） which is with a lower adsorbing energy give a significant effect on the molecular structure of CH4/Si mixture.The obtained data and conclusion in this paper will be applied in the fields of the sensitive to methane of silicon surface and gas sensor technology.

关 键 词：甲烷 硅表面 物理吸附 密度泛函理论 

分 类 号：O561.1[理学—原子与分子物理]