Electronic states of Sb, Bi, Au, and Sn clusters on GaAs(110)

Using Hellmann–Feynman molecular dynamics, one can calculate the atomic motion, equilibrium geometries, and electronic states for clusters of atoms on semiconductor surfaces. Here we report studies that were motivated by the scanning tunneling microscopy and spectroscopy observations of Feenstra and co‐workers. Although the geometries and electronic structures vary from one simulation to another, we typically find states in or near the upper part of the band gap for Sb, Bi, Au, and Sn on GaAs(110). The character of these states is rather complicated and geometry dependent, but they tend to be largely associated with the cluster and the surface Ga atoms. That is, they can be roughly viewed as split off from the Ga‐derived conduction bands by the perturbation resulting from the semiconductor–cluster bonding.