Annealing effects on faceting of InAs∕GaAs(001) quantum dots

Abstract

The aspect ratio and faceting evolution of quantum dots grown at 500°C were studied as a function of postgrowth annealing temperature. We show that faceting and aspect ratio strictly depend on growth conditions. The evolution toward ͕136͖ and ͕137͖ facets is kinetically limited and occurs under different experimental conditions. Furthermore long annealing procedures lead to the occurrence of low aspect ratio domes different from those forming at higher growth temperatures.

Manipulating surface diffusion and elastic interactions to obtain quantum dot multilayer arrangements over different length scales

“…We have found that the dots nucleating on the mound side opposite the direction of the As flux tend to dissolve 11,21 and their material move to the other side in a sort of ripening effect. 22,23 To explain the vertical stacking of dots, shown in Fig. 2(b), we observe first that, at high growth temperature, the adatom (Ga and In) diffusion is greatly enhanced.…”

Single QD emission from arrays of QD chains obtained by patterning-free method

“…1c and d are grown with the same growth parameters (including the same average growth rate) except for the growth interruptions, the better order for the PD sample is clearly related to the longer time available for the island ripening process, in absence of the In-flux, which contributes to achieve more uniform size distribution. 24,25 In addition, in the CD sample we find the presence of a higher density of very large island (probably containing dislocations) in comparison to the PD sample. Evidently, the ripening is more effective to uniform the size and avoid the formation of very large island when the In flux is not continuously delivered.…”

Growth and characterization of site‐selective quantum dots

“…It is known that at lower temperatures QDs tend to ripen whereas they dissolve at higher temperatures [21,22]. In situ annealing experiments with self-assembled QDs have confirmed the power of this technique to alter properties such as QD size, shape, and ordering [23][24][25]. The fact that QDs undergo morphological changes during annealing remained, however, unattended with respect to positioned QDs.…”