Adsorption of selenium atoms at the Si(111)-7 x 7 surface: A combination of scanning tunnelling microscopy and density functional theory studies

作者：Wu S Q; Zhou Yinghui; Wu Qi Hui^*; Pakes C I; Zhu Zi Zhong

来源：Chemical Physics, 2011, 382(1-3): 41-46.

DOI：10.1016/j.chemphys.2011.02.006

• Selenium
• Si(111)-7 x 7
• STM
• Density functional theory

The adsorption of selenium (Se) atoms at the Si(1 1 1)-7 x 7 surface has been investigated using both scanning tunnelling microscopy (STM) and density functional theory calculations. A single Se atom prefers to adsorb at sites close to a Si adatom and bonds with this Si adatom and one of its backbonding Si atoms. The adsorption sites are referred to as A*-type sites in this article. The density of the conduction band (empty states) of the Si adatom increases as a result of the adsorption of a Se atom, which causes the Si adatom to become brighter in the empty state STM images. At the same time, the adsorption of the Se atom weakens the bonding between the Si adatom and its backbonding Si atom due to the charge transfer from them to the Se atom, and consequently destructs the ordered Si(1 1 1)-7 x 7 surface with increasing Se coverage.

• 出版日期2011-4-28
• 单位厦门大学