Electrical barriers at semiconductor interfaces: Some reflections and future challenges

Interfaces between semiconductors and insulators, metals or other semiconductors play a crucial role in the behaviour of solid state electronic devices. It is therefore no surprise that techniques to accurately control the electronic properties of such interfaces has long been an ambitious goal. Here we consider some of the key contributions to this area over several decades, concentrating in particular on the role of dipole layers at semiconductor interfaces. We consider the current state of our understanding with respect to the fabrication of microelectronic and optical devices. Furthermore, we present views on some of the future challenges particularly in high performance optical devices and nanostructures