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Related papers: Mechanisms of GaN quantum dot formation during nit…

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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…

The investigation of small size embedded nanostructures, by a combination of complementary anomalous diffraction techniques, is reported. GaN Quantum Dots (QDs), grown by molecular beam epitaxy in a modified Stranski-Krastanow mode, are…

Materials Science · Physics 2009-11-11 J. Coraux , V. Favre-Nicolin , H. Renevier , M. G. Proietti , 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

It is shown that quantum effects play determining role in nitrogen adatom diffusion due to several different factors. This could be related to the change of the energy of the quantum states and also due to the redistribution of electrons…

Materials Science · Physics 2025-02-24 Paweł Strak , Cyprian Sobczak , Stanislaw Krukowski

GaN and the heterostructures are attractive in condensed matter science and applications for electronic devices. We measure the electron transport in GaN/AlGaN field-effect transistors (FETs) at cryogenic temperature. We observe formation…

Mesoscale and Nanoscale Physics · Physics 2021-03-11 Tomohiro Otsuka , Takaya Abe , Takahito Kitada , Norikazu Ito , Taketoshi Tanaka , Ken Nakahara

Quantum dots can be formed in simple GaN/AlGaN field-effect-transistors (FETs) by disordered potential induced by impurities and defects. Here, we investigate the channel length dependence of the formation of quantum dots. We observe…

Mesoscale and Nanoscale Physics · Physics 2023-07-20 Kazuma Matsumura , Takaya Abe , Takahito Kitada , Takeshi Kumasaka , Norikazu Ito , Taketoshi Tanaka , Ken Nakahara , Tomohiro Otsuka

Using 3D k.p calculation including strain and piezoelectricity we predict variation of electronic and optical properties of InAs/GaAs quantum dots (QDs) with the substrate orientation. The QD transition energies are obtained for high index…

Materials Science · Physics 2015-06-25 V. Mlinar , F. M. Peeters

We describe the optical emission and the carrier dynamics of an ensemble of self-assembled GaAs quantum dots embedded in GaP(001). The QD formation is driven by the 3.6 % lattice mismatch between GaAs and GaP in Stranski-Krastanow mode…

Mesoscale and Nanoscale Physics · Physics 2016-03-23 S. Dadgostar , J. Schmidtbauer , T. Boeck , A. Torres , O. Martínez , J. Jiménez , J. W. Tomm , A. Mogilatenko , W. T. Masselink , F. Hatami

The diffusion of Ga and N adatoms has been studied for the technologically relevant wurtzite (000bar1) and (0001) surfaces employing density-functional theory. Our calculations reveal a very different diffusivity for Ga and N adatoms on the…

Condensed Matter · Physics 2009-10-31 T. Zywietz , J. Neugebauer , M. Scheffler

The interaction of Mn with Ge quantum dots (QD), which are bounded by {105} facets, and the strained Ge wetting layer (WL), terminated by a (001) surface, is investigated with scanning tunneling microscopy (STM). Mn is deposited on the Ge…

Materials Science · Physics 2012-10-31 C. A. Nolph. J. K. Kassim , J. A. Floro , P. Reinke

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

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…

Understanding the atomic-scale mechanisms governing metal-mediated nucleation and growth of gallium nitride (GaN) and related alloys is critical for tailoring their structural and functional properties in advanced electronic,…

We perform spatial point analysis of InAs quantum dot nucleation sites and surface reconstruction domain pattern on an InAs wetting layer, giving insights for quantum dot nucleation mechanism. An InAs wetting layer grown to 1.5 monolayers…

Materials Science · Physics 2015-05-19 Tomoya Konishi , Shiro Tsukamoto

The nanowire-supported quantum dot (NWQD) of GaN is an unconventional nanostructure, which is extremely promising for realization of UV photonics in general, and room-temperature single photon generation, in particular. While GaN-NWQDs have…

Applied Physics · Physics 2022-08-19 Swagata Bhunia , Ritam Sarkar , Dhiman Nag , Dipankar Jana , Suddhasatta Mahapatra , Apurba Laha

We theoretically model the formation of quantum dots(QDs) and quantum dot molecules(QDMs) in silicon germanium heteroepitaxy by explicitly incorporating the role of noise in a continuum theory for surface evolution in molecular beam…

Mesoscale and Nanoscale Physics · Physics 2022-01-26 Monika Dhankhar , Madhav Ranganathan

Embedding quantum dots (QDs) on nanowire (NW) sidewalls allows the integration of multi-layers of QDs into the active region of radial p-i-n junctions to greatly enhance light emission/absorption. However, the surface curvature makes the…

Mesoscale and Nanoscale Physics · Physics 2021-04-01 Yunyan Zhang , H. Aruni Fonseka , Hui Yang , Xuezhe Yu , Pamela Jurczak , Suguo Huo , Ana M. Sanchez , Huiyun Liu

We report on the growth and optical characterisation of droplet GaAs quantum dots with extremely-thin (11 nm) capping layers. To achieve such result, an internal thermal heating step is introduced during the growth and its role in the…

This work presents some fundamental features of pyramidal site-controlled InGaAs Quantum Dots (QDs) grown by MetalOrganic Vapour Phase Epitaxy on patterned GaAs (111)B substrate. The dots self-form inside pyramidal recesses patterned on the…

In this work, we explore a method for obtaining site-controlled InAs quantum dots (QDs) on large areas of GaAs (0 0 1) pre-patterned surface. The patterning of the substrate is obtained by using a monolithically integrated nano-channel…

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