The atomic structure of the $\sqrt{3}\times \sqrt{3}$ phase of silicene on Ag(111)

Abstract

The growth of the $\sqrt{3}\times \sqrt{3}$ reconstructed silicene on Ag substrate has been frequently observed in experiments while its atomic structure and formation mechanism is poorly understood. Here by first-principles calculations we show that $\sqrt{3}\times \sqrt{3}$ reconstructed silicene is constituted by dumbbell units of Si atoms arranged in a honeycomb pattern. Our model shows excellent agreement with the experimentally reported lattice constant and STM image. We propose a new mechanism for explaining the spontaneous and consequential formation of $\sqrt{3}\times \sqrt{3}$ structures from $3\times 3$ structures on Ag substrate. We show that the $\sqrt{3}\times \sqrt{3}$ reconstruction is mainly determined by the interaction between Si atoms and have weak influence from Ag substrate. The proposed mechanism opens the path to understanding of multilayer silicon.

References in corpus (1)

• Valley-Polarized Metals and Quantum Anomalous Hall Effect in Silicene

Cited by in corpus (5)

• Silicite: the layered allotrope of silicon
• Adsorption of Group-IV Elements on Graphene, Silicene, Germanene, Stanene: Dumbbell Formation
• Dissociative Adsorption of Molecules on Graphene and Silicene
• Structural stability and energy-gap modulation through atomic protrusion in freestanding bilayer silicene
• Crossover between Silicene and Ultra-Thin Si Atomic Layers on Ag(111) Surfaces