New Identification of Metallic Phases of In Atomic layers on Si(111) Surfaces

TL;DR

This study uses first-principles calculations to identify the atomic structures and electronic properties of metallic indium layers on silicon surfaces, clarifying previous ambiguities about their coverage and structure.

Contribution

It provides the first detailed atomic and electronic characterization of In overlayers on Si(111), correcting prior assumptions about their structure and periodicity.

Findings

The two metallic phases are single and double In overlayers.

Calculated energy bands match experimental STM images.

The phases have distinct atomic structures and energetics.

Abstract

We report first-principles calculations that clarify atomic structures and coverage of the metallic phases of In overlayers on Si (111) surfaces. Calculated energy bands and scanning tunneling microscopy images along with the obtained energetics of various phases reveal that the two metallic phases with the $\sqrt{7} \times \sqrt{3}$ periodicity observed experimentally are single and double In overlayers, as opposed to prevailing assignments.