Universal building block for (1 1 0)-family silicon and germanium surfaces

TL;DR

This study introduces a universal atomic building block for (1 1 0) silicon and germanium surfaces, validated through first-principles calculations and experimental STM data, unifying various surface reconstructions.

Contribution

It proposes a universal atomic building block for (1 1 0) surfaces, enabling accurate modeling of multiple reconstructions and resolving debates on pentagon structures.

Findings

Models show very low surface energies.

Excellent agreement with STM images.

Shared building block confirmed on Si(47 35 7) surface.

Abstract

The universal building block which is an essential part of all atomic structures on (1 1 0) silicon and germanium surfaces and their vicinals is proposed from first-principles calculations and a comparison of results with available experimental data. The atomic models for the (1 1 0)-(16x2), (1 1 0)-c(8x10), (1 1 0)-(5x8) and (17 15 1)-(2x1) surface reconstructions are developed on the basis of the building block structure. The models exhibit very low surface energies and excellent agreements with bias-dependent scanning tunneling microscopy (STM) images. It is shown experimentally using STM that the Si(47 35 7) surface shares the same building block. Our study closes the long-debated pentagon structures on (1 1 0) silicon and germanium surfaces.