单个砷原子在砷化镓富砷表面的迁移行为

Diffusion Behaviors of an Extra As Atom on GaAs As-rich Surface

采用分子动力学方法计算了单个砷原子在砷化镓(001)β2(2×4)富砷表面迁移的势能面,研究了砷原子在该表面上的迁移行为。结果表明,在该表面存在一部分低能量的吸附位和一条平行于砷二聚体的迁移路径。且在这条迁移路径中,砷原子迁移所需要跃过的势垒均小于0.6 eV.因此在常温情况下,砷原子有可能在这条迁移路径中聚合成团簇。

The potential energy surface for the migration of an extra As atom on the GaAs（001） β2（2 ＆#215; 4）surface was mapped out to study the diffusion behaviors of As atom by performing molecular dynamics simulations. The results＆amp;nbsp;show that there existed some lower-energy sites and one possible pathway paralleling to the As dimers in this sur-face for the adsorption and diffusion of an extra As atom, and the energy barrier for the diffusion of As atom was less than 0. 6 eV in the pathway. Therefore, the As atoms are likely to form clusters in the pathway at ambient tem-perature.