Analysis of Nanostructures by EM Techniques: Quantum Dots

Nanostructures have gained increasing interest in materials science due to their special mechanical, electrical and optical behavior. The correlation between these extraordinary properties and the morphology and crystal structure can be analyzed by combining numerous electron-optical techniques. The present contribution demonstrates the successful application to semiconductor quantum dots. TEM techniques is focused on the determination of parameters, such as shape and size of islands, their chemical composition and the complex lattice strain fields. A successful image contrast analysis in terms of shape and strain demands the application of image simulation techniques based on the many-beam dynamical theory and on structure models refined by molecular dynamics or molecular static energy minimization.