Photoluminescence and structural properties of unintentional single and double InGaSb/GaSb quantum wells grown by MOVPE

Ahia, Chinedu Christian; Tile, Ngcali; Botha, J.R.; Olivier, E.J.

doi:10.1016/j.physb.2017.06.007

Cited by 9 publications

(7 citation statements)

References 19 publications

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“…To date, a consensus is yet to be reached with regards to the emission wavelength of InSb/GaSb QDs. In this paper, we extend our previous investigations 11,12 and report on the effect of stacking on the NIR-PL properties of unintentional InGaSb/GaSb QWs, formed during an attempt to fabricate capped InSb/GaSb QDs.…”

Section: Introductionsupporting

confidence: 67%

“…Irrespective of the epitaxial technique adopted, the development of InSb/GaSb QDs has been reported 6,7 to be challenging due to the relatively weak indium-antimony (In-Sb) binding energy, which gives rise to a long migration length of In adatoms on an Sb-terminated surface. Many studies [8][9][10] have reported PL emission of InSb/GaSb QDs within the near-IR (NIR) region; however, transmission electron microscopy (TEM) studies reported recently 11,12 have illustrated the inadvertent formation of an InGaSb quantum well (QW) after capping of InSb QDs, which gave rise to PL spectra similar to what has earlier been reported by some groups [8][9][10] to be emission from InSb QDs within the NIR region. Emission within the MIR region have been reported 6 for this material system.…”

Section: Introductionmentioning

confidence: 77%

“…A more detailed description of the growth procedure and sample preparation has been reported elsewhere. 11,12 All the layers in the samples used for this study were deposited without growth interruption. of InSb QD layers embedded between the GaSb buffer and cap layers for each sample, while the fourth sample in which uncapped InSb dots were grown directly on a 300 nm GaSb buffer layer was used as a reference for SPM studies.…”

Section: Methodsmentioning

confidence: 99%

“…A detailed description of the low energy PL lines in this study and their behaviour with laser power and temperature has been reported elsewhere. 11,12 …”

Section: -8mentioning

confidence: 99%

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Long wavelength stacking induced shift of the near-infrared photoluminescence from unintentional MOVPE grown InGaSb/GaSb quantum wells

et al. 2018

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The effect of stacking on the near-infrared photoluminescence (NIR-PL) of InGaSb/GaSb quantum wells (QWs) which were inadvertently formed during an attempt to fabricate stacked InSb/GaSb quantum dots (QDs) using atmospheric pressure Metalorganic Vapor Phase Epitaxy (MOVPE) are investigated in this work. The morphology of uncapped dots was studied by means of scanning probe microscopy (SPM) which shows a significant deviation in the shape and density of dots grown directly on the buffer compared to those that terminated an “embedded-dot” sample. Cross-sectional scanning transmission electron microscopy (STEM) and transmission electron microscopy (TEM) of the capped structures clearly revealed the formation of QWs in the capped structures. An increase in the number of InSb QD-layers, which metamorphosed into QWs, was observed to cause an increase in the luminescence spectral line width and a long-wavelength shift of the QW PL lines, together with an enhancement in the strength of PL emission. Variations in layer thicknesses and alloy composition introduced as a result of inter-diffusion of Ga and In which is enhanced by the prolonged annealing time of the QDs (during spacer/cap layer deposition) and In adatom migration is suggested to alter the morphology of the capped dots and induce a change in PL peak positions and the spectral linewidth of the NIR low energy lines.

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Section: Introductionsupporting

confidence: 67%

Section: Introductionmentioning

confidence: 77%

Section: Methodsmentioning

confidence: 99%

“…A detailed description of the low energy PL lines in this study and their behaviour with laser power and temperature has been reported elsewhere. 11,12 …”

Section: -8mentioning

confidence: 99%

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Long wavelength stacking induced shift of the near-infrared photoluminescence from unintentional MOVPE grown InGaSb/GaSb quantum wells

et al. 2018

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“…Initially, their optical properties are evaluated by UV-visible [89] and photoluminescence spectroscopy [90,91], which is a fast and nondestructive technique allowing for the excitation, absorption, and emission spectra used for calculation of quantum yield to be determined [92].…”

Section: Box 2 Characterization Of Quantum Dotsmentioning

confidence: 99%

Biological Applications and Toxicity Minimization of Semiconductor Quantum Dots

Filali

Pirot

Miossec

2020

Trends in Biotechnology

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Determining the Structural Properties and Vibrational Modes of Annealed Lead Composite Material Deposit

Ahia,

Meyer,

Umeh

2024

Physica Status Solidi (a)

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Techniques for effectively harnessing lead (Pb) deposits for optimum utilization have attracted a lot of research interest. Results obtained from investigating the elemental composition, vibrational modes, and structural properties of a fired Pb composite deposit, which was purified using an electric kiln furnace and further annealed in palladium‐diffused hydrogen ambient, are reported in the present study. Both atomic force microscopy (AFM) and scanning electron microscopy (SEM) analysis on the deposit indicate that the Pb composite is composed of crystal‐like morphology. The vibrational modes obtained from the material are identical to the Raman spectrum reported for PbSO4 (anglesite). Also, data acquired from the energy dispersive X‐ray (EDX) analysis of the annealed Pb composite material confirmed the presence of zinc (Zn), carbon (C), silicon (Si), sulfur (S), and oxygen (O) in the material. At the same time, Pb appeared to be the primary constituent with reference to its weight percentage composition compared to other elements. Using the Fourier transform infrared (FTIR) spectroscopy technique, a slight shift in peak positions to higher wavenumbers was observed for most of the frequency bands in the FTIR spectrum compared to their position in the Raman spectrum. The cause of the shift in wavenumber is still subject to investigation but can be tentatively ascribed to be induced by factors such as a decrease in bond length because of modification in electronegativity of the atom or structural changes at the subatomic level. The photoluminescence (PL) spectra obtained from the sample showed overlapped weak emission bands which were observed in the ultraviolet (UV) and visible (VIS) region, while a small optical band gap of ∽ 0.1307 eV was extrapolated through the Tauc plot for the Pb composite material using a direct band gap transition approach. The findings from the present study may be vital for providing an improved understanding of the electronic and structural properties of the annealed Pb composite deposit, while promoting the development of a feasible approach for the recovery and recycling of Pb for future related applications.This article is protected by copyright. All rights reserved.

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Photoluminescence and structural properties of unintentional single and double InGaSb/GaSb quantum wells grown by MOVPE

Cited by 9 publications

References 19 publications

Long wavelength stacking induced shift of the near-infrared photoluminescence from unintentional MOVPE grown InGaSb/GaSb quantum wells

Long wavelength stacking induced shift of the near-infrared photoluminescence from unintentional MOVPE grown InGaSb/GaSb quantum wells

Biological Applications and Toxicity Minimization of Semiconductor Quantum Dots

Determining the Structural Properties and Vibrational Modes of Annealed Lead Composite Material Deposit

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