Diplomarbeit Diplom-Ingenieur - Institut für Halbleiter

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The equilibrium shape is constructed with these first tree Miller planes. The shape
built up with these planes is a small cubo-octahedron, or, for the special case that the
{110} and {001} interfaces are quadratic, a rhombi-cubo-octahedron (see Fig.2.7).
The definition of a cubo-octahedron is the combined shape of a cube and an
octahedron which leads to a cube with truncated edges and corners. The {001}
interfaces represent the original cube interfaces. There are manifold appearances of
the cubo-octahedron if the sizes of the chopped parts, which build the {110} and
{111} interface classes, changes. The equilibrium shape has important consequences
for interface characterisation. The interface must be parallel to the electron beam for
interface characterisation with high resolution TEM imaging. The {111} interfaces of
the QDs are of triangular shape. If this interface is parallel to the electron beam and is
focused, the projected length of the interface changes and makes it difficult to image
this interface.
Figure 2.7: A small rhombi-cubo-octahedron. The {100} and {110} surfaces have the
same area and are quadratic. Each facet has a parallel associate surface. The shape is
highly symmetric. The {111} surfaces are triangles.