Chapter 3 - Quantum Nanostructures (QDs): An Overview

Abstract

Materials exhibit fascinating properties when one or more of their dimensions is reduced to the nanometer scale. One of the most immediate observations when reducing the size of materials to the nanometer scale is the confinement in the movement of electrons due to the quantum confinement effect. This leads to discretization of electron energy levels depending on the confinement size of the material. The resulting structure exhibits interesting novel optoelectronic, physicochemical, mechanical, and magnetic properties not shown by the corresponding bulk structures of the same material. This chapter presents insights on quantum nanostructures, which are classified according to their degrees of quantization, especially quantum dots (QDs). Further, the special properties exhibited by zero-dimensional structures, such as photoluminescence, multiple exciton generation, and size tunable bandgap, are discussed. This chapter also introduces various synthesis and fabrication processes used to fabricate QDs in exclusive applications, such as displays, biological labels, and photovoltaics.