一种可能的InP(100)(4×2)表面原子结构模型

对于用氩离子刻蚀并在磷气氛中退火得到的InP(100)(4×2)再构表面,用HREELS测得表面的In—H和P—H键几乎是同时形成的,而用偏振光UPS观察时,P的悬挂键电子态并不具有沿原胞两个周期方向的对称性质。根据这些结果,可以推测InP(100)的富In表面存在In的空位,与In空位相邻的P原子悬挂键发生了转向。我们提出了一种失列-二聚物原子结构模型。它可以定性地解释所观察到的实验事实。关键词：

A POSSIBLE SURFACE ATOMIC STRUCTURE MODEL OF InP (100) (4×2) RECONSTRUCTION

The InP(l00) (4×2) reconstructed surface prepared by argon ion bombardment and post annealing under phosphorus pressure has been investigated by LEED, HREELS and UPS. It was found by HREELS that the forming of surface In-H and P-H bonds during hydrogen exposure happened almost simultaneously. By measuring the UP spectra using polarized light sources, it can be verified that the dangling bond states of surface P atoms do not possess the symmetrical characteristic with respect to the two basis vector directions of surface unit mesh. It could be deduced from the above evidences that there must exist some In vacancies on the In-rich InP (100) surface, and the dangling bonds of those P atoms which are located next to the In vacancies orientate off their normal directions. We propose here a missing row-dimer model for the atomic arrangement of InP (100) (4×2) stucture, which could explain the observed experimental qualitatively and might be used as a working model for seeking a precise surface structural model.