Shape, size, and number density of InAs quantum dots grown on the GaAs(1¯1¯3¯)B surface at various temperatures

Abstract

InAs quantum dots ͑QD's͒ were grown on the GaAs͑113͒B surface by molecular-beam epitaxy at temperatures between 435 and 490°C. Their shape, size, and number density were investigated by in-situ scanning tunnelling microscopy. The shape of the QD's is given for the most part by ͕110͖, ͑111͒B, and vicinal ͑001͒ bounding facets, and does not change significantly with growth temperature. The diameter at the base and the height of the QD's increase monotonously from 25 to 54 nm, and from 3.5 to 9.8 nm, respectively, whereas the number density decreases as temperature increases. This is explained by assuming a slight decrease of the number density of critical growth nuclei with increasing temperature. The size distribution is bimodal: besides the coherent QD's, some larger and probably incoherent islands are observed that are extended along ͓332͔. Post annealing increases the diameter and the height by about 30% and decreases the number density, but does not change the shape significantly.

InAs quantum dots grown on theGaAs(113)AandGaAs(1¯1¯3¯)Temko1, Suzuki2, Kratzer3 et al. 2003Phys. Rev. BSelf Cite310170View full textAdd to dashboardCite

“…Therefore, the QD growth starts simultaneously at the SK transition and the QD's grow with equal rates, resulting in a homogeneous size distribution. 47 Here we observe a case of growth limitation. Since the SK transition is rather short in time, we are unable to observe embryo dots.…”

“…The flat base, which was not observed on the QD's on GaAs͑113͒A, is an intrinsic part of the InAs QD's on GaAs (1 1 3 )B, which appears not only during growth, but still exists after annealing treatment of the samples. 47 As described in Ref. 14, two symmetrical facets 1 and the triangular facet 2 from the main part were identified to be ͕110͖ and (1 1 1 )B(ͱ19 ϫ ͱ19) surfaces, respectively.…”

Effect of growth temperature on InAs wetting layer grown on (113)A GaAs by molecular beam epitaxy

“…This effect can be related at the independent of the QDs density with indium depositing. Suzuki et al [31] have studied the number density of the InAs QDs grown on GaAs ð113ÞB at different temperatures by in situ scanning tunnelling microscopy. They have observed that the number density, decreases with increasing temperature in spite of the important amount of InAs that has been deposited at high growth temperature.…”

A comprehensive study of the effect of in situ annealing at high growth temperature on the morphological and optical properties of self-assembled InAs/GaAs QDs

“…In addition to these peaks there are some weak side peaks which represent irregular sized islands. These islands having non-uniform size distribution are relaxed and incoherent in nature due to the presence of dislocations, and the distribution of these irregular sized islands is controlled by a surface diffusion of adatoms at elevated temperatures, not by strain [21]. In Figs.…”