Characterisation of the structure and composition of quantum dots
Electron microscopy with its associated microanalytical techniques is the ideal tool for investigating the structure of quantum dots (QDs) nucleated from strained layers. The optical and electronic properties of these dots depend upon their size, shape and composition - parameters which electron microscopy makes a claim to be able to provide. But, because of their complex geometry, these parameters have proved difficult to obtain. This paper describes a series of experiments which provide detailed information on QD structures, and particularly their composition, in the Ge/Si and InGaAs/GaAs systems.