ABSTRACT
In a nanowire (NW), the momentum of an electron is con ned in two directions, thus allowing for electron motion only in one direction (a NW is a one degree of freedom structure and is o en called a one-dimensional nanostructure if its diameter is less than 100 nm). is reduction in dimensionality results in dramatic quantum e ects dependent on wire material, axis orientation, length, and diameter. ese quantum e ects in NWs change the electrical, chemical, and mechanical properties to name but a few. us, NWs exhibit properties and applications very di erent from their bulk form. erefore, they have been assiduously studied recently by experimentalists and theorists for their potential applications in electronic devices and sensors. Investigations for a thorough theoretical understanding of the structure-property relationship for many NWs and NW devices are currently in progress across scienti c and engineering disciplines. is research is being carried out on the theoretical side by a multi-scale approach to the atomic simulation of these materials. On the experimental side, a careful study of growth, characterization, and device assembly is ongoing. is chapter gives a brief introduction to this twofold approach. Ample references for further study are also provided. is chapter is divided into ve sections. Section 16.2 brie y reviews an elementary NW model derived from the steady-state (time-independent) Schrödinger equation. e aim of this section is to show the profound e ect dimensionality has on the electronic properties of a nanostructure. Section 16.3 reviews some Ge NW growth experiments and measurements of Ge NW properties. e electrical, optical, mechanical, and surface properties of Ge NW along with their applications are dealt with brie y in Section 16.4. Section
16.5 introduces some of the simulation methods used to study NWs and describes their capabilities and limits and Section 16.6 forms the conclusion.
