Optimizing the growth procedure for InAs quantum dot stacks by optical in situ techniques

Lateral shape of InAs/GaAs quantum dots in vertically correlated structures

“…6, a better homogeneity of the QD size in the topmost layer of VCQDS with the spacer thickness of 3.7 nm is evident, this effect has also been reported elsewhere [6,7]. Since the QDs in the last layer are almost entirely located on the hillocks covering the underlying QDs, we conclude that the QD density does not change with the number of QD layers and the level of vertical correlation is high in our structures.…”

Atomic-scale structure of self-assembled In(Ga)As quantum rings in GaAs

“…We attribute the presence of the second indium layer to the accumulation of segregated indium from the wetting layer at the surface of the partial capping layer and to surface migration of indium atoms that have been expelled from the quantum dots during QR formation. [18][19][20][21] We find that the second indium layer is not only present nearby the nanostructures, but actually extends laterally over the entire cleaved surface. However, by closer inspection of Fig.…”

Formation of InAs wetting layers studied by cross-sectional scanning tunneling microscopy

“…17 Recently, we observed that during this process, a second layer of indium accumulates on the surface of the capping layer, which is due to vertical segregation of indium from the WL and to lateral migration on the surface of indium atoms that have been expelled from the QDs during QR formation. [18][19][20][21] After continued capping, the second layer of indium, itself, forms a segregated indium distribution.…”