Enhanced Stability of Heterostructures Under Pressure

Abstract

Epitaxial heterostructures configured as single or repeated layers, and, more recently, as islands, have become ubiquitous within semiconductor physics because of the diverse phenomena and applications made possible through their tailored growth.[1] The practical limits of heterostructure tailoring are defined by a variety of instabilities related to bulk, interface, and local bonding properties, and the study of these instabilities offers fundamental insight into the competition between mechanical and chemical forces at each structural level. Despite the importance of such issues, most experimental and theoretical work on heterostructure stability has been limited to external environments compatible with growth, and, hence, has not considered the effects of extreme hydrostatic pressure.[2–4] Although this is understandable in terms of current interest trends, it overlooks the nature of pressure as a thermodynamic parameter capable of shifting heterostructures into regions of phase space which ordinarily are either inaccessible, or only attained in chemically different materials systems.