Multilayer silicene: clear evidence

One year after the publication of the seminal paper on monolayer 3 × 3 reconstructed silicene grown on a silver (111) substrate, evidence of the synthesis of epitaxial √3 × √3 reconstructed multilayer silicene hosting Dirac fermions was presented. Although a general consensus was immediately reached in the former case, in the latter, 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 °C), while three-dimensional growth of silicon crystallites takes place at higher temperatures, (~300 °C). This transition to bulk-like silicon perfectly explains the various data presented and discussed in the literature and solves their conflicting interpretations.