Buckled Silicene Formation on Ir(111)

TLDR

This study aims to develop a method for producing high‑quality silicene and to explain the formation of its buckled sheet on Ir(111). The authors fabricate silicene on Ir(111) by depositing silicon onto the substrate and characterize the resulting (√3×√3) silicene/(√7×√7)Ir(111) buckled structure using low‑energy electron diffraction, scanning tunneling microscopy, and first‑principles calculations. Silicene was successfully fabricated on Ir(111) as a (√3×√3) buckled honeycomb lattice with a (√7×√7) superstructure, confirmed by LEED, STM, and density‑functional theory, and the electron localization function indicates two‑dimensional continuity of the silicon adlayer.

Abstract

Silicene, a two-dimensional (2D) honeycomb structure similar to graphene, has been successfully fabricated on an Ir(111) substrate. It is characterized as a (√7×√7) superstructure with respect to the substrate lattice, as revealed by low energy electron diffraction and scanning tunneling microscopy. Such a superstructure coincides with the (√3×√3) superlattice of silicene. First-principles calculations confirm that this is a (√3×√3)silicene/(√7×√7)Ir(111) configuration and that it has a buckled conformation. Importantly, the calculated electron localization function shows that the silicon adlayer on the Ir(111) substrate has 2D continuity. This work provides a method to fabricate high-quality silicene and an explanation for the formation of the buckled silicene sheet.