Formation of Silicon Quantum Dots Sheet on a Nonmetallic CaF₂ Surface

Abstract The research on the atomic layer 2D materials employed in ultrahigh‐speed electronic devices has attracted significant attention and silicene, a monoatomic layer allotrope of Si, is considered the most effective material. For practical device applications, it is necessary to grow silicene on a nonmetallic substrate; however, only the growth of silicene on metallic or semiconductive substrates is reported. In this study, Si quantum dot sheets are grown on a nonmetallic epitaxial CaF₂ surface by the deposition of monolayer thick Si. By depositing Si at a temperature ranging from room temperature to 650 °C, a 2D sheet composed of high‐density quantum dots (7.8 × 10¹² cm⁻²) is obtained. Scanning tunneling spectroscopy and X‐ray photoelectron spectroscopy measurements reveal that Si forms a continuous film containing quantum‐sized dots on the CaF₂ surface.