Multilayer Silicene: a clear evidence

TL;DR

This paper provides definitive crystallographic evidence that multilayer silicene can be synthesized at low temperatures, clarifying previous debates and distinguishing it from bulk silicon growth at higher temperatures.

Contribution

It demonstrates through x-ray crystallography that multilayer silicene is effectively realized at low growth temperatures, resolving conflicting interpretations in prior studies.

Findings

Multilayer silicene forms at ~200°C.

3D silicon crystallites grow at ~300°C.

The transition explains previous conflicting data.

Abstract

One year after the publication of the seminal paper on monolayer 3 by 3 reconstructed silicene grown on a silver (111) substrate, evidence of the synthesis of epitaxial root3 by root3 reconstructed multilayer silicene hosting Dirac fermions was presented. Although a general consensus was immediately reached in the former case, in the latter one, the mere existence of multilayer silicene was questioned and strongly debated. Here, we demonstrate by means of a comprehensive x-ray crystallographic study, that multilayer silicene is effectively realized upon growth at rather low growth temperatures (~200{\deg}C), while, instead, 3D growth of silicon crystallites takes place at higher temperatures, (~300{\deg}C). This transition to bulk like silicon perfectly explains the various data presented and discussed in the literature and solves their conflicting interpretations.