利用第一原理理论研究了金属In在Si(001)表面吸附的原子结构.结果表明,In原子的吸附不破坏村底Si的二聚体化学键.在低覆盖率时,In原子在Si(001)村底上形成有序量子线,取向沿村底Si的二聚体化学键方向.计算结果显示相邻In线之间不存在排斥作用.
Using first-principles method, we investigate the structural properties of In on Si(001) surface. The adsorption energy of In on ideal Si(001)-(1 × 1) surface is significantly higher than that on reconstructed Si (001)-(2 × 1) surface. It is shown that adsorption of In atoms does not break the Si-Si dimer bond of the sub- strate. The calculated configurations of In quantum wire growth on Si(001)-(2 × 1) surface are (i) In quantum wire parallel to the Si dimer bond of the substrate (along the [1 1 0] direction) and (ii) In quantum wire perpendicular to the Si dimer bond of the substrate (along the [1 1 0] direction). Total energy optimizations also show that the energetically favored model is that In quantum wire is parallel to the Si dimer bond. According to the atomic distances after relaxing, we can conclude that the repulsion between adjacent In chains is very weak.