(Color online) X-STM images of the InGaAs WL as a function of the capping layer thickness. (a) 2 nm, (b) 3 nm, (c) 6 nm first capping layer thickness, and (d) conventionally grown capping layer.
(Color online) In segregation as a function of first capping layer thickness and bilayer position from the start of the WL.
(Color online) X-STM image of one conventionally grown QD and three QDs grown with an indium flush step incorporated in the growth process. The thickness of the first capping layer was varied.
(Color online) QD height (black points) as a function of the thickness of the first capping layer. The black line is a linear fit. The dotted red line represents the sum of the critical layer thickness (5 ML) and the first capping layer thickness (dashed blue line). The experimentally determined average thickness of the final WL is given by the open red boxes.
(Color online) Two 60 nm × 15 nm X-STM images. (a) InAs QD capped with InP after a 30 s GI. (b) InAs QD capped with InP after a 30 s GI + 30 s GISb. The bright spots correspond to Sb atoms.
QD height distribution of (a) uncapped InAs QDs, (b) InP capped InAs QDs, (c) InP capped InAs QDs after 30 s GISb, and d) GaAsSb capped InAs QDs after 5 s GISb.
(Color online) Two 100 nm × 20 nm X-STM images of InAs QDs and the WL capped with (a) 1 nm and (b) 2 nm GaAsSb after a 30 s GI + 5 s GISb. A single step edge is visible at the left side in both images.
(Color online) 40 nm × 34 nm topographic image of a typical GaAs/AlGaAs QD (top) and an average cross-sectional profile (top graph) and separation between bilayers (bottom graph) along the line in the top figure.
(Color online) 30 nm × 60 nm topographic image (left) of two QDs. An atomic grid is overlain on top of a close up of the QD dot (right). Al and Ga atoms in the QD are indicate by, respectively, dark and light squares.
(Color online) Profile of three QDs extracted from the X-STM data (open circles). A Gaussian function is fitted to the largest QD. The other two QDs are assumed to have the same 3D-structure as the largest QD but cleaved off center. The projection of the (111)-direction on the cleavage plane is given by the dashed black line.
Article metrics loading...
Full text loading...