Self-assembled quantum dots

Progress in nanoscience and nanotechnology requires tools to characterise
the structure of objects on an atomic level. Semiconductor "quantum dots"
are well-known examples of nanoscale systems. Germanium islands grown
spontaneously and self-organised on a silicon substrate are extensively
investigated as model systems.

a) An AFM (Atomic Force Microscope) image of a germanium quantum dot on silicon shows its external shape. b) and c) X-ray scattering techniques reveal its internal structure. (Image credits: a) T.H. Metzger + M-I. Richard; b) + c) A. Malachias, copyright 2005 A. Malachias).

Further information:

• Atomic Ordering in Self-assembled Ge Quantum Dots

• T.U. Schülli et al., Phys. Rev. Lett., 90, 066105 (2003).
• A. Malachias et al., Phys. Rev. B, 72, 165315 (2005).