Шаблон:ChemboxIndium(II) selenide (InSe) is an inorganic compound composed of indium and selenium. It is a III-VI layered semiconductor. The solid has a structure consisting of two-dimensional layers bonded together only by van der Waals forces. Each layer has the atoms in the order Se-In-In-Se.[1]
Indium(II) selenide can be formed via a number of different methods. A method to make the bulk solid is the Bridgman/Stockbarger method, in which the elements indium and selenium are heated to over 900 °C in a sealed capsule, and then slowly cooled over about a month.[3] Another method is electrodeposition from a water solution of indium(I) sulfate and selenium dioxide.[4]
Properties
There are three polytopes or crystal forms. β, ε are hexagonal with unit cells spanning two layers. γ has rhombohedral crystal system, with the unit cell including four layers.[1]
β-Indium(II) selenide can be exfoliated into two-dimensional sheets using sticky tape. In a vacuum these form smooth layers. However when exposed to air, the layers become corrugated because of chemisorption of air molecules.[5] Exfoliation can also take place in isopropanol liquid.[6]
Indium (II) selenide is stable in ambient conditions of oxygen and water vapour, unlike many other semiconductors.[1]
The properties of indium(II) selenide can be varied by way of altering the exact ratio of elements from 1:1, creating vacancies. It is hard to get an exact equality. The properties can be compensated by transition element doping. Other elements that can be included in small concentrations are boron,[7]silver,[8] and cadmium.[9]