DFT study of Rb/Si(100)-2x1 System

TL;DR

This study uses density functional theory to analyze how rubidium atoms adsorb on silicon surfaces at different coverages, revealing the most stable configurations and electronic properties, and comparing findings with experiments.

Contribution

It provides a comprehensive DFT analysis of Rb adsorption on Si(100)-2x1, identifying stable structures and electronic characteristics at various coverages.

Findings

Symmetrized dimers are more stable at 1 ML coverage.

Half ML coverage favors symmetrical dimers in the most stable model.

Electronic properties such as work function and surface states are characterized.

Abstract

We have investigated Rb adsorption on the Si(100) surface for 0.5 and 1 monolayer coverages using the total energy method with norm-conserving pseudopotentials. For 2$\times$1 reconstruction at 1 ML coverage symmetrized dimers are found to be energetically more favorable. On the other hand, half a ML coverage is found to have symmetrical dimers only for the most stable adsorption model. All possible surface-adatom configurations have been considered in the calculations to find which adsorption sites are energetically favored. In addition to the structural properties, the interface is investigated electronically for the work function and surface states. The results are discussed and compared with the existing experimental findings.