Epitaxial challenges

The expertise of the group for the epitaxy of a wide range of semiconductor nanostructures allows together (i) to develop thematic explorations in material science (such as nucleation mechanisms or new forms of materials i.e. nanowires), (ii) to provide on demand samples for internal or external studies at the local, national and international levels, and (iii) to propose new kinds of nano-objects for new functionalities and potential applications.

Over the period, a special interest was paid to nanowire (NW) heterostructures, which open a way to grow quantum objects whatever the lattice mismatch with barrier material. In these structures, the quantum dot (QD) can be a thin slice of small gap material inserted in a narrow NW with a position, shape and size determined by the growth conditions, by contrast to the Stranski-Kratstanov QDs, which are due to a self-assembled process having the elastic strain relaxation as a driving force. This gives rise to a lot of new possibilities for the engineering of these QDs embedded into NWs: QDs of GaN, InGaN, GaAs, CdSe, CdTe, CdMnTe were inserted into NWs made of respectively AlN, GaN, AlGaAs, ZnSe, ZnTe barriers. Depending on the semiconductor compounds, the axial growth to achieve these NWs is a vapor-liquid-solid growth process, which is done either without any catalyst (nitrides), either with a self-catalyst (gallium for arsenides) or with a gold catalyst (II-VI materials). These nanowire based structures are optimized using both Molecular Beam Epitaxy (MBE) and Metal-Organic Chemical Vapor Deposition (MOCVD).

Besides this expertise, the control of the radial growth in these 1D structures was also developed; it permits:

  • a proper choice of the shell around the NW, which allows tailoring the strain in the QD and achieving electrical doping;
  • an efficient passivation of the surface in order to inhibit the surface non-radiative recombination channels;
  • a growth of multi-quantum wells on non-polar planes (facets of the NWs) such as InGaN /GaN or GaN / AlInN.

Moreover, the easy dispersion of NWs afterwards makes possible the study of structural, optical and electrical properties of single objects, which is one of the main research lines of our group.

Quantum coherence - CQ

Quantum coherence - CQ

Revealing quantum phenomena in electronic nano-circuits
Helium : from fundamental to applications - HELFA

Helium : from fundamental to applications - HELFA

Helium as model system, hydrodynamic and turbulence, space and astrophysics, instrumentation and cryogenic development, kinetic inductance detectors.
Magnetism and Superconductivity - MagSup

Magnetism and Superconductivity - MagSup

Team Magnetism and Superconductivity at Institut NEEL - Systems involving charge, spin or lattice degrees of freedom.
Optics and materials - OPTIMA

Optics and materials - OPTIMA

a complete chain of competences that goes from the design and elaboration of new materials to the study of nonlinear optical properties and plasmonics
Materials, Radiations, Structure - MRS

Materials, Radiations, Structure - MRS

Understanding of the physico-chemical properties of complex materials based on the precise description of their structure
Micro and NanoMagnetism - MNM

Micro and NanoMagnetism - MNM

Complementary expertise in fabrication, characterisation, and simulations for studies in nanomagnetism with applications in spin electronics and micro-systems
Quantum Nano-Electronics and Spectroscopy - QNES

Quantum Nano-Electronics and Spectroscopy - QNES

Electron transport and local spectroscopy of quantum structures
Nano-Optics and Forces - NOF

Nano-Optics and Forces - NOF

Nano - optics and forces
Nanophysics and Semiconductors - NPSC

Nanophysics and Semiconductors - NPSC

Growth of III-V and II-VI semiconductor nanostructures and their physics in search of new functions for potential applications.
Nanospintronics and Molecular Transport - NanoSpin

Nanospintronics and Molecular Transport - NanoSpin

Studying magnetism at the nanoscale, where classical and quantum properties can be combined and used for molecular quantum spintronics
Wide bandgap semiconductors - SC2G

Wide bandgap semiconductors - SC2G

Physics of diamond and other wide bandgap semiconductors towards applications in electronics and biotechnologies
Surfaces, Interfaces and Nanostructures - SIN

Surfaces, Interfaces and Nanostructures - SIN

Experimental and theoretical studies of low dimensional systems
Hybrid systems at low dimensions - HYBRID

Hybrid systems at low dimensions - HYBRID

Electronic, optical, vibrational, mechanical properties, as well as their interplay at the nanoscale, of novel hybrid systems (nanotubes, graphene, two-dimensional and functionalized materials) which are developed by the group .
Condensed Matter Theory - TMC

Condensed Matter Theory - TMC

Novel physical phenomena in materials and model systems.
Thermodynamics and Biophysics of small systems - TPS

Thermodynamics and Biophysics of small systems - TPS

Ultra-sensitive instrumentation for electrical and thermal measurements: from biophysics to low temperature condensed matter physics.
Theory of Quantum Circuits - ThQC

Theory of Quantum Circuits - ThQC

Theoretical studies of electronic transport in nanometer-scale devices showing remarkable quantum effects.
Ultra-low temperatures - UBT

Ultra-low temperatures - UBT

Quantum physics at the ultra-low temperature frontier.

A quantum dot in a nanowire : GaN/AlN, CdSe/ZnSe, ...

We have developed the growth techniques for semiconductor nanowires based on different material systems such as III-N (InN, GaN, AlN], II-VI(,CdSe,ZnSe) and III-As (InAs, GaAs, AlAs). Currently, these nanowires have demonstrated single photon operation respectively in the UV and in the visible.... > suite

Semiconductor nanowires for ultimate magnetic objects

Our research aims to fabricate, study, and manipulate different forms of magnetic polarons embedded in semiconductors nanowires. One challenge is to make a link between the quantum limit (single magnetic impurity, single carrier), and ferromagnetic-like system involving an ensemble of magnetic impurities and several carriers confined in a quantum dot, or a one dimensional hole gas. It may open also new routes for semiconductor structures embedding ferromagnetic elements, in the search for higher ordering temperatures by wavefunction engineering, for controlled anisotropy by strain engineering, and for strong magneto-electric effects.

Non-polar and polar nitrides quantum dots

People : Edith Bellet-Amalric, Bruno Daudin, Henri Mariette Benoît Amstatt, Johann Coraux, Sébastien Founta Overview and results : Study of the growth and of structural and optical properties of GaN quantum dots (QDs) obeys several motivations, from both basic and applied research points... > suite

Elaboration of II-VI quantum dots

People: Régis ANDRE, Catherine BOUGEROL, Hervé BOUKARI, Henri MARIETTE, Serge TATARENKO. Thomas AICHELE, Laurent MAINGAULT, Rita NAJJAR, Ivan-Christophe ROBIN Results: CdSe/ZnSe self-organized QDs The case of CdSe differs from other strained materials such as Si/Ge or InAs/GaAs: the... > read more

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