Electronic structure of the Si(111)-√21x√21-(Ag+Au) surface
Electronic structure of the Si(111)-√21x√21-(Ag+Au) surface
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DOI：
10.1103/physrevb.57.9015
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发表时间：
1998-04-15
影响因子：
3.7
通讯作者：
Hasegawa, S
中科院分区：
文献类型：
--
作者：
Tong, X;Jiang, CS;Hasegawa, S
利用角分辨紫外和X射线光电子能谱分析了室温下Si（111）-root 21 x root 21（R+/-10.89度）-（Ag+Au）表面上0.19原子层的Au吸附诱导的电子能带结构。我们发现了两个内在的色散表面态带交叉的费米能级，这被认为是源于反键的初始根3x根3-Ag结构的表面状态。发现这些带中积累的电子是由Au吸附原子贡献的。电子从Au吸附原子转移到衬底体（表面空间电荷层）也证实了通过测量能带弯曲的变化。结果似乎与原子模型一致，其中Au吸附原子位于根3x根3-Ag骨架的Ag三聚体的顶部。我们提出了一种原子键合机制，在这个表面上，被称为“寄生表面键合”，其中Au吸附原子通过衬底表面的表面态带的金属键。[S0163-1829（98）02515-6]。
Angle-resolved ultraviolet and x-ray photoelectron spectroscopies were used to analyze the electronic band structure of the Si(111)-root 21x root 21(R+/-10.89 degrees)-(Ag+Au) surface that was induced by Au adsorption of 0.19 atomic layer onto the Si(111)-root 3x root 3-Ag surface at room temperature. We found two intrinsic dispersive surface-state bands crossing the Fermi level, which were considered to originate from an antibonding surface state of the initial root 3x root 3-Ag structure. The electrons accumulated in these bands were found to be donated by Au adatoms. The electron transfer from Au adatoms into the substrate bulk (surface space-charge layer) was also confirmed by measuring the changes in band bending. The results seemed to be consistent with an atomic model in which the Au adatoms sit atop the Ag trimers of the root 3x root 3-Ag framework. We proposed a kind of atomic bonding mechanism on this surface, referred to as "parasitic surface bonding," where Au adatoms make metallic bonds via a surface-state band of the substrate surface. [S0163-1829(98)02515-6].