ABSTRACT
This chapter discusses a novel approach to the optimisation of quantum dot bilayer structures grown by molecular beam epitaxy. It shows that vertically stacked quantum dot structures often exhibit an increase in the average size of the islands with increasing number of quantum dot layers deposited. The understanding of the In segregation induced Stranski-Krastanow transition suggests that this is due to excess of In caused by elemental segregation. As the sizes of such islands are comparable with the De Broglie wavelength for electrons, a strong confinement of carriers is expected with a resulting 8-like density of states, making the nanostructures ideal candidates for applications as quantum dots in the field of optoelectronics. The kinetic model of segregation is used in order to estimate the reduction in the fraction of In to be deposited on the second layer, in order to obtain increased uniformity in the size distribution along the quantum dot stack and to optimise the optical emission.
