Si/Ge nanostructures

Abstract

A review is given on the formation mechanisms and the properties of Si/Ge nanostructures that have been synthesized by self-assembling and self-ordering during heteroepitaxy of \mbox{silicon-germanium} alloys on single-crystal silicon substrates. The properties of electronic subbands in smooth strained Si/SiGe quantum well structures are presented as a basis for characterizing coherent Si/Ge nanostructures with free motion of carriers in a reduced number of dimensions. The low-dimensional band structure of valence band states confined in strained Si/Ge and Si/SiGe nanostructures is analysed by optical and electrical spectroscopy.