NanOp - Animations

Growth of a Quantum Dot

by Frank Heinrichsdorff, TU-Berlin

This animation shows the evolution of a single quantum pyramid in self organized epitaxial growth (so called Stranski-Krastanov growth mode). The movie starts with a view on the surface of the Gallium-Arsenide substrate which is covered with a single layer of Indium-Arsenide. Each single sphere represents a single atom. The epitaxial growth starts imediately. This looks like a rainfall of further blue spheres. The additional atoms stick to the surface but are still able to move along the surface. After the deposition of the amount of another monolayer the flux of atoms is stopped. The formation of another closed monolayer, however, is energetically not favourable. Thus the atoms start to form a litle clusters which then evolves to a whole pyramid.

This movie is just a very simple model to illustrate what might happen during the self organized growth of quantum dots. This model is very much a mechanical model, treating atoms as hard spheres. It does not take care about quantum mechanics, chemical bonds, surface effects like desorbtion and so on. Actually nobody has ever seen what "really" happens during the growth of a quantum dot.

Growth of a Quantum Dot

MPEG-Movie (6 MB)