CH_3OH在Ga-rich GaAs(001)-(4×2)表面上的吸附与解离:团簇模型的密度泛函计算

Adsorption and dissociation of CH_3OH on the Ga-rich GaAs( 001)-(4 × 2)surface: DFT computations with a cluster model

采用简单团簇模型结合密度泛函理论研究了CH3OH在Ga-rich Ga As(001)-(4×2)表面上的吸附与解离过程.计算结果表明,CH3OH在Ga-rich Ga As(001)-(4×2)表面上首先会形成两种化学吸附状态,然后CH3OH经解离生成CH3O自由基和H原子吸附在表面不同位置上.通过比较各个吸附解离路径,发现解离后的H原子相对更容易吸附在位于表面第二层紧邻的As原子上.

Based on a simple cluster model, the adsorption and dissociation processes of CH3OH molecule on the Garich GaAs（001 ） - （4 x 2） surface have been studied with density functional theory. The present computa tions demonstrate that two chemisorbed states are formed initially, and then, the CH3OH molecule will decompose to CH3 0 radical and H atom on the surface. By comparing different adsorption and decomposition pathways, it is found that the dissociated H atom tends to be chemisorbed on the adjacent As atom at the second layer.