M ardi 5 Juin K223 9H30
Prof. Paul Koenraad (Eindhoven University, Hollande)
"Atomic scale analysis of semiconductor quantum dots"
In the talk I will present recent results that we have obtained by cross-sectional Scanning Tunneling Microscopy (X-STM) and Atom Probe Tomography (APT) on a range semiconductor nanostructures such as quantum dots and rings. The X-STM technique offers a superb 2D true atomic resolution in a single atomic plane intersecting the nanostructure. Atom Probe Tomography is a technique that has recently become available for the structural analysis of semiconductor nanostructures. Laser induced field emission is used to get a 3D map of the composition of semiconductor nanostructure. The composition profiles that can be reconstructed from the APT data of for instance quantum dots have a near atomic resolution. In the talk I will apply and compare these techniques on quantum dots and rings that have been obtained by various growth procedures such as the traditional Stransky-Krastonow process, droplet epitaxy or by applying Sb during the dot formation process.