Study the surface structure evolution of Si-adsorption on Ag(111) by LEED-AES

Silicene, the silicon analogy of graphene, has attracted tremendous attention. Also the formation of alloys that exist only in a confined region near the surface of materials has important technological implications. In this work, we study the structural transition for silicon adsorption on Ag(111) to form a highly ordered 2-D structure and to observe the alloy formation of Si-Ag as an example of semiconductor-metal system. We obtained a mixer phase of (4×4) and (3.5×3.5) R 26° at 470 K and 490 K; a mixer free pure (4×4) structure at 520 K, which is silicene, a highly ordered 2-D honeycomb structure of silicon; and a mixer free (3.5×3.5) R 26° structure at 620 K, which indicated the alloy formation of Si-Ag with two-third monolayer silicon coverage on Ag(111).