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Related papers: Step by step capping and strain state of GaN/AlN q…

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Grazing incidence anomalous x-ray scattering was used to monitor in situ the molecular beam epitaxy growth of GaN/AlN quantum dots (QDs). The strain state was studied by means of grazing incidence Multi-wavelength Anomalous Di raction (MAD)…

Materials Science · Physics 2007-05-23 J. Coraux , H. Renevier , V. Favre-Nicolin , G. Renaud , B. Daudin

We report a correlative microscopy study of a sample containing three stacks of InGaN/GaN quantum dots (QDs) grown at different substrate temperature, each stack consisting of 3 layers of QDs. Decreasing the substrate temperature along the…

Materials Science · Physics 2021-06-08 I. Dimkou , J. Houard , N. Rochat , P. Dalapati , E. Di Russo , D. Cooper , A. Grenier , E. Monroy , L. Rigutti

A detailed theoretical study of the optical absorption in self-assembled quantum dots is presented in this paper. A rigorous atomistic strain model as well as a sophisticated electronic band structure model are used to ensure accurate…

We have examined the formation mechanisms of GaN quantum dots (QDs) via annealing of Ga droplets in a nitrogen flux. We consider the temperature and substrate dependence of the size distributions of droplets and QDs, as well as the relative…

Materials Science · Physics 2020-02-26 H. Lu , C. Reese , S. Jeon , A. Sundar , Y. Fan , E. Rizzi , Y. Zhuo , L. Qi , R. S. Goldman

We study the nucleation of GaN islands grown by plasma-assisted molecular-beam epitaxy on AlN(0001) in a Stranski-Krastanov mode. In particular, we assess the variation of their height and density as a function of GaN coverage. We show that…

Materials Science · Physics 2017-01-17 C. Adelmann , B. Daudin , R. A. Oliver , G. A. D. Briggs , R. E. Rudd

GaN nanowires (NWs) grown by molecular beam epitaxy on Ti films sputtered on Al$_{2}$O$_{3}$ are studied by X-ray diffraction (XRD) and grazing incidence small-angle X-ray scattering (GISAXS). XRD, performed both in symmetric Bragg…

Cubic GaN layers were grown by plasma-assisted molecular beam epitaxy on 3C-SiC (001)substrates. In situ reflection high energy electron diffraction was used to quantitatively determine the Ga coverage of the GaN surface during growth.…

Materials Science · Physics 2007-05-23 J. Schoermann , S. Potthast , D. J. As , K. Lischka

In this work, we present conception and study of gallium nitride (GaN) nanostructures on a gallium arsenide (GaAs) substrate with (111)A orientation. The nanostructures were designed by GaN droplet epitaxy and studied in-situ by X-ray…

We investigate the strain state of ensembles of thin and nearly coalescence-free self-assembled GaN nanowires prepared by plasma-assisted molecular beam epitaxy on Ti/Al$_{2}$O$_{3}(0001)$ substrates. The shifts of Bragg peaks in…

Conventional ultraviolet (UV) lamps for disinfection emit radiation in the 255-270 nm range, which poses a high risk of causing cancer and cataracts. To address these concerns, solid-state far UV-C sources emitting below 240 nm are gaining…

A theoretical interpretation of the photoluminescence excitation spectra of self-organized polar GaN/(Al,Ga)N quantum dots is proposed. A numerical method assuming a realistic shape of the dots and including the built-in electric field…

Mesoscale and Nanoscale Physics · Physics 2015-06-19 D. Elmaghraoui , M. Triki , S. Jaziri M. Leroux , J. Brault

The paper reports on fundamental properties of the GaN/AlN quantum wells (QWs) with nominal subcritical thicknesses of 0.75-2 monolayers (MLs). They are grown by plasma-activated molecular beam epitaxy, varying either the nominal thickness…

Over the past two decades, epitaxial semiconductor quantum dots (QDs) have demonstrated very promising properties as sources of single photons and entangled photons on-demand. Among different growth methods, droplet etching epitaxy has…

Geometric phase analysis has been applied to high resolution aberration corrected (scanning) transmission electron microscopy images of InAs/GaAs quantum dot (QD) materials. We show quantitatively how the lattice mismatch induced strain…

The optical properties of excitons confined in initially-unstrained GaAs/AlGaAs quantum dots are studied as a function of a variable quasi-uniaxial stress. To allow the validation of state-of-the-art computational tools for describing the…

In this paper, we describe the growth and characterization of 530-nm-thick superlattices (100 periods) of AlxGa1-xN/AlN (x = 0, 0.1) Stranski-Krastanov quantum dots for application as the active region of electron-beam pumped ultraviolet…

Strain-free GaAs/AlGaAs semiconductor quantum dots (QDs) grown by droplet etching and nanohole infilling (DENI) are highly promising candidates for the on-demand generation of indistinguishable and entangled photon sources. The…

We use strain to statically tune the semiconductor band gap of individual InAs quantum dots (QDs) embedded in a GaAs photonic wire featuring very efficient single photon collection efficiency. Thanks to the geometry of the structure, we are…

Mesoscale and Nanoscale Physics · Physics 2018-03-22 D. Tumanov , N. Vaish , H. A. Nguyen , Y. Curé , J. -M. Gérard , J. Claudon , F. Donatini , J. -Ph. Poizat

We present an atomistic study of the strain field, the one-particle electronic spectrum and the oscillator strength of the fundamental optical transition in chemically disordered In$_{x}$Ga$_{1-x}$As pyramidal quantum dots (QDs).…

Materials Science · Physics 2007-05-23 R. Santoprete , P. Kratzer , M. Scheffler , R. B. Capaz , Belita Koiller

Few-layer GaSe is one of the latest additions to the family of 2D semiconducting crystals whose properties under strain are still relatively unexplored. Here, we study rippled nanosheets that exhibit a periodic compressive and tensile…

Mesoscale and Nanoscale Physics · Physics 2019-03-07 David Maeso , Sahar Pakdel , Hernan Santos , Nicolas Agrait , Juan Jose Palacios , Elsa Prada , Gabino Rubio-Bollinger
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