Structural and optical properties of vertically aligned InP quantum dots

Abstract

Stacked layers of self-assembled InP quantum dots embedded in Ga0.52In0.48P have been prepared by solid source molecular beam epitaxy. Thereby the distance between the dot layers has been varied from 2 to 16 nm. Cross sectional transmission electron microscopy shows that the InP dots are aligned in the growth direction [100]. As the distance between the dot layers is reduced, each dot of the first dot layer is reproduced in the upper layers, and this leads to an improvement of the dot size homogeneity of the stacked InP dot system. This is confirmed by photoluminescence (PL) measurements, which demonstrate a very narrow linewidth of 26 meV for a triple layer with 2 nm separation between the dot layers in comparison with a linewidth of 41 meV for a single layer sample. At the same time, the PL peak of the dots is shifted by 72 meV to lower energies which is ascribed to a reduced strain and strong electrical coupling between the densely stacked InP dots.

Increase of charge-carrier redistribution efficiency in a laterally organized superlattice of coupled quantum dots

“…In the case of self-assembled QDs, coupling is typically considered in the context of the ground states of vertically stacked dots, separated by a thin layer of matrix ͑barrier͒ material. A number of groups have reported coupling of, for example, vertically stacked InAs/ GaAs, 26 InAs/ InP, 27 InP / GaInP, 28 and InGaAs/ InGaAsP ͑Ref. 29͒ dots.…”

Size, density, and shape of InAs quantum dots in closely stacked multilayers grown by the Stranski–Krastanow mode

“…3,4 We now consider a column with intermediate layers of a thickness d and n layers of islands ͑Fig. 1͒.…”

Self-assembling nanostructures and atomic layer precise etching in molecular beam epitaxy

“…The 0.9 ixm thick p-and n-type doped energy electron diffraction (RHEED) have been AlInP cladding layers are surrounding the observed during in-situ etching of GaAs using iodine Ga 0 . 52 In 0 .48P wave guide layer which contains the [13,14], AsC1 3 [15][16][17][18], AsBr3 [19][20][21] and tris-3-fold stack of InP dots [1,9]. Under pulsed operadimethylaminoarsenic (TDMAAs) [22][23][24][25][26][27].…”

“…This new techsion of the strain field [1]. nique may become important in future for the A cross-sectional transmission electron micropreparation of monolithically integrated devices graph (TEM) of the QD laser structure is shown in which involve two epitaxial growth steps with Fig.…”

“…Thin epitaxial layers are prepare by applying Stranski-Krastanow growth prepared by MBE for fast transistors and laser diodes mode in strained layer heteroepitaxy [1]. Interesting in industrial production systems.…”