A new series of two-dimensional silicon crystals with versatile electronic properties. (20th February 2018)

• Record Type: Journal Article
• Authors: Chae, Kisung; Kim, Duck Young; Son, Young-Woo
• Is Part Of: 2D materials. Volume 5:Number 2(2018)
• Publication Date: 2018-02-20
• Subjects: first principles calculations -- new silicon crystals -- ab initio structure search method; Graphene -- Periodicals; Materials science -- Periodicals; Nanostructured materials -- Periodicals; 620.115
• DOI: 10.1088/2053-1583/aaac9f
• Languages: English
• ISSNs: 2053-1583

Abstract

Abstract: Silicon (Si) is one of the most extensively studied materials owing to its significance to semiconductor science and technology. While efforts to find a new three-dimensional (3D) Si crystal with unusual properties have made some progress, its two-dimensional (2D) phases have not yet been explored as much. Here, based on a newly developed systematic ab initio materials searching strategy, we report a series of novel 2D Si crystals with unprecedented structural and electronic properties. The new structures exhibit perfectly planar outermost surface layers of a distorted hexagonal network with their thicknesses varying with the atomic arrangement inside. Dramatic changes in electronic properties ranging from semimetal to semiconducting with indirect energy gaps and even to one with direct energy gaps are realized by varying thickness as well as by surface oxidation. Our predicted 2D Si crystals with flat surfaces and tunable electronic properties will shed light on the development of silicon-based 2D electronics technology.