page_title: Two-dimensional materials
section_title: Silicene
hierarchical_section_title: Two-dimensional materials / 2D allotropes / Silicene
caption_attribution_description: STM image of the second-layer √3 × √3-β silicene at 620 K, which appeared at Si coverage = 2.0 ML. The image size is 16 × 16 nm. Vs = +2.0 V, I = 0.1 nA.
context_page_description: Two-dimensional materials, sometimes referred to as single-layer materials, are crystalline materials consisting of a single layer of atoms. These materials have found use in applications such as photovoltaics, semiconductors, electrodes and water purification.
  2D materials can generally be categorised as either 2D allotropes of various elements or as compounds. The elemental 2D materials generally carry the -ene suffix in their names while the compounds have -ane or -ide suffixes. Layered combinations of different 2D materials are generally called van der Waals heterostructures.
  The efficient integration of 2D functional layers with three-dimensional systems remains a significant challenge, limiting device performance and circuit design.
  Some 700 2D materials have been predicted to be stable, although many remain to be synthesized. The global market for 2D materials is expected to reach US$390 million by 2025, mostly for graphene in the semiconductor, electronics, battery energy and composite materials markets.
context_section_description: Silicene is a two-dimensional allotrope of silicon, with a hexagonal honeycomb structure similar to that of graphene.
caption: STM image of the first (4×4) and second layers (√3×√3-β) of silicene grown on a thin silver film. Image size 16×16 nm.
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