Quantum dots: substrate nanopatterning as a path towards the applications

Abstract

Nanotechnology aims at exploiting the remarkable size effects that arise when materials are reduced to nanoscale dimensions. Exploiting such effects will lead to new applications in different areas of human endeavour. The self assembly of three-dimensional islands is one of the most promising paths towards the fabrication of artificial atoms, or quantum dots (QDs) devoted to nanoelectronic and nanophotonic applications. In order to exploit the unique electronic properties of semiconductor quantum dots in novel quantum effect devices, lateral dimensions of these structures have to be reduced to the order of tens of nm’s, the range of De Broglie wavelength of electrons inside these materials. Moreover, millions of quantum dots should be orderly packed in dense arrays to achieve the necessary active volume. So far, the most promising quantum structures have been fabricated using techniques based on self assembling, but their ordering is possible only by appropriate substrate nanopatterning. In this paper we will explore different ways of patterning a substrate and how they affect the growth and ordering of the quantum dots.