Quantum dot structures in the InGaAs system investigated by TEM techniques

Quantum dot structures have gained increasing interest in materials science due to their special electrical and optical behavior. A combination of ele ctron-optical techniques is applied to correlate such proper-ties with the morphology and structure of quantum dots in the InGaAs system. TEM techniqu es, e.g. imaging by conventional diffraction contrast, by high-resolution T EM and by energy filtering (EFTEM) are focused on the determination of para meters, like shape and size of islands, their chemical composition and the complex lattice strain fields. An image contrast analysis in terms of shape and strain demands the application of image simulation techniques based on the dynamical theory and on structure models refined by molecular dynamics or molecular static energy minimization.