層状物質基板

抄録

Layered materials, represented by graphite, mica, MoS₂ or GaSe, have a lamellar structure consisting of two-dimensional unit layers. Each unit layer is formed via strong covalent or ionic type bonds, while there is no strong bond between two unit layers; they are bound together via van der Waals-type weak interaction. Then layered materials can be easily cleaved and the clean cleaved surface has a very wide and flat terrace without an active dangling bond. When the thin film growth is investigated on such an inactive surface of a layered material, only weak interaction works between the substrate and the grown material. This results in far small lattice-mismatch distortion in the grown film even if it has a different lattice constant or a crystal structure from the substrate. Consequently, single-crystalline heteroepitaxial growth of layered materials or organic molecular crystals can be achieved from the initial layer on the layered material substrate. In this paper we will explain structure, physical property and usage of some layered material substrates.