In–Mole-Fraction and Thickness of Ultra-Thin InGaAs Insertion Layers Effects on the Structural and Optical Properties of InAs Quantum Dots

2007 ◽  
Vol 31 ◽  
pp. 132-134
Author(s):  
P. Boonpeng ◽  
S. Panyakeow ◽  
S. Ratanathammaphan

InAs quantum dots (QDs) have been grown by solid-source molecular beam epitaxy on different InxGa1-xAs (0 ≤ x ≤ 0.3) to investigate the effect of In-mole-fraction and thickness of InGaAs insertion layer (IL) on the structural and optical properties of the QDs. The density of QDs directly grown on GaAs is 1×1010 cm-2, and increase to 1.4-1.8×1010 cm-2 on InGaAs layers which depend on the In-mole-fraction and thickness of InGaAs layers. The effects of In-mole-fraction and thickness of InGaAs insertion layer on optical properties of the QDs are studied by photoluminescence (PL). The FWHM of PL spectrum corresponds to the size distribution of the QDs.

2004 ◽  
Vol 38 (3) ◽  
pp. 340-343 ◽  
Author(s):  
I. P. Soshnikov ◽  
N. V. Kryzhanovskaya ◽  
N. N. Ledentsov ◽  
A. Yu. Egorov ◽  
V. V. Mamutin ◽  
...  

2008 ◽  
Vol 39 (11) ◽  
pp. 1248-1250 ◽  
Author(s):  
A. Pulzara-Mora ◽  
E. Cruz-Hernández ◽  
J.S. Rojas-Ramírez ◽  
V.H. Méndez-García ◽  
M. López-López

Author(s):  
Suwit Kiravittaya ◽  
Kamonchanok Khoklang ◽  
Supachok Thainoi ◽  
Somsak Panyakeow ◽  
Somchai Ratanathammaphan

GaSb quantum dots (QDs) have been grown by solid-source molecular beam epitaxy on a 4-monolayer (ML) InxGa1-xAs (x = 0.07, 0.15, 0.20, and 0.25) to investigate the effects of In-mole-fraction of InGaAs insertion layers on the structural and optical properties of the GaSb QDs. The density of grown GaSb QDs is approximately 1.2-2.8109 cm−2 on In-GaAs insertion layers which depends on the In-molefraction. Dot shape and size change substantially when In-mole-fraction of InGaAs insertion layers is varied. The uniformity of GaSb QDs improves when the indium content increases. The change in freestanding QD morphology is likely due to the modified strain at different values of indium compositions in InGaAs insertion layers. The effects of In-molefraction of InGaAs insertion layer on optical properties of the QDs are studied by photoluminescence (PL). PL results show the blueshift of the emission when the indium content in InGaAs insertion layer increases.


2011 ◽  
Vol 2011 ◽  
pp. 1-5
Author(s):  
Faouzi Saidi ◽  
Mouna Bennour ◽  
Lotfi Bouzaïene ◽  
Larbi Sfaxi ◽  
Hassen Maaref

We have investigated the optical properties of InAs/GaAs (113)A quantum dots grown by molecular beam epitaxy (MBE) capped by (In,Ga)As. Reflection high-energy electron diffraction (RHEED) is used to investigate the formation process of InAs quantum dots (QDs). A broadening of the PL emission due to size distribution of the dots, when InAs dots are capped by GaAs, was observed. A separation between large and small quantum dots, when they are encapsulated by InGaAs, was shown due to hydrostatic and biaxial strain action on large and small dots grown under specifically growth conditions. The PL polarization measurements have shown that the small dots require an elongated form, but the large dots present a quasi-isotropic behavior.


2006 ◽  
Vol 955 ◽  
Author(s):  
Tim Michael Smeeton ◽  
Mathieu Sénès ◽  
Katherine L Smith ◽  
Stewart E Hooper ◽  
Jon Heffernan

ABSTRACTThe structural and optical properties of InGaN quantum dots grown by plasma-assisted molecular beam epitaxy (MBE) have been characterised using atomic force microscopy, high-resolution transmission electron microscopy (TEM), Z-contrast scanning TEM, micro-photoluminescence (PL), temperature dependent PL and time-resolved PL. The uncapped InGaN nano-islands have densities of ∼1.5 × 1011 cm−2, heights of (1.7 ± 1.0) nm and diameters of (10 ± 4) nm. These parameters are not substantially changed during overgrowth of a GaN cap and the resulting quantum dots have a composition of In0.15Ga0.85N. The observation of narrow luminescence peaks in micro-PL measurements proves light emission from discrete energy states and the optical properties indicate strong confinement of carriers in the quantum dots and an unusually weak impact of piezoelectric field effects.


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