IEMN
  • Accueil
  • Actualités
    • Newsletters de l’IEMN
    • Offres de Stages M2-Ingé
    • Les offres d’emplois
    • Toutes les actualités
  • L’Institut
    • Présentation
    • Organisation de l’institut
    • La Direction Scientifique
    • La Direction Technologique
    • La direction administrative et financière
    • Règlement intérieur
    • Nos engagements
  • La Recherche
    • Les départements scientifiques
      • Matériaux Nanostructures et Composants
      • Micro/nano et optoélectronique
      • Technologies des télécommunications et Systèmes intelligents
      • Acoustique
    • Les groupes de recherche
    • Les projets phares
  • Production Scientifique
    • Publications IEMN
    • Ressources production scientifique
  • Les plateformes
    • CMNF – Plateforme Centrale de Micro Nano Fabrication
      • Pôle Gravure et implantation
      • Pôle Analyse In Line
      • Pôle Soft Lithographie et Bio Microfluidique
      • Pôle Dépôts et épitaxie
      • Pôle Lithographie
      • Pôle Packaging
      • Staff CMNF
    • PCMP – Plateforme de Caractérisation Multi-Physique
      • Pôle Microscopie en Champ Proche (PCP)
      • Pôle Caractérisation Hyperfréquence, Optique et Photonique (CHOP)
      • Pôle Systèmes de COMmunications avancées et prototypage (SigmaCOM)
      • Pôle Caractérisation et Compatibilité ElectroMagnétique et prototypage (C2EM)
      • Staff PCMP
    • Prestations proposées par nos plateformes
  • Partenariat – Valorisation
    • Les Collaborations Académiques
    • Projets ANR
    • Principales collaborations internationales
    • Les partenariats industriels
    • Les laboratoires communs IEMN-Industrie
    • Les startups
  • La Formation à la Recherche
    • L’après-thèse
      • Faire un post-doc à l’IEMN
      • Vers le monde des entreprises et de l’industrie
      • Devenir Enseignant-Chercheur
      • Devenir Chercheur
      • Créer son entreprise à l’IEMN
      • FOCUS sur un ingénieur SATT issu de l’IEMN
    • Une thèse à l’IEMN
      • Soutenances de thèses et HDR
      • Sujets de thèses
      • Les financements
      • Les études doctorales
    • Master – Ingénieur
      • Masters ULille
        • Master Life Sciences and Technologies graduate program
        • Master Nanosciences and Nanotechnologies – Speciality ETECH
        • Master Réseaux et Télécommunications
      • Masters UPHF-INSA
        • Master Ingénierie des Systèmes embarqués et Communications Mobiles
        • Master Cyber-Défense et Sécurité de l’information
        • Master Matériaux, Contrôle, Sécurité
        • Master Ingénierie des Systèmes Images et Sons
      • Écoles Ingé partenaires/tutelles
      • Offres de Stages M2-Ingé
    • Le pôle lillois du GIP-CNFM
    • Nano-École Lille
  • Contact
    • Localisation
    • Formulaire de contact
    • Annuaire Intranet
    • « Suivez-nous »
  • Nos soutiens
  • en_GB
  • Rechercher
  • Menu Menu
GROUPE DE RECHERCHE : PHYSIQUE
GROUPE DE RECHERCHE : PHYSIQUE

Atypical electron confinement in semiconductor nano-platelets

The reduction in size of semiconductor materials to the nanometer scale allows to restrict the degree of freedom of electron motion (or dimensionality) along 1, 2 or 3 directions in space. To date, due to growth constraints, the study of electron behavior has been limited to materials with strict dimensionalities (1D, 2D or 3D). An original study shows that materials obtained by colloidal chemistry processes can have a hybrid dimensionality, intermediate between 2D and 1D.

In massive materials, the properties of the charge carriers, i.e., the electrons, are directly derived from the materials themselves, independently of the external environment. However, this paradigm is no longer valid when these materials are reduced to the nanoscale. Indeed, at this scale, the degree of freedom of movement of electrons depends strongly on the size and shape of the materials. This strong dependence gives rise to spectacular effects such as the modification of the color of the light emitted by the same material by simply modifying its size as shown in figure 1. This color variation is associated with a modification of the electron energy induced by the quantum confinement. At the nanoscale, the degree of freedom of movement of electrons in materials, also called dimensionality (D), can be precisely controlled.  Thus in carbon nanotubes, known as 1D, electrons can only propagate freely along the length of the tube.

The technological progress of the last twenty years has led to the development of standard materials allowing the exploration of electronic and optical properties associated with the different dimensionalities. Thus colloidal nanocrystals, carbon nanotubes, quantum wells obtained by epitaxy constitute the references for 0D, 1D, 2D dimensionalities respectively. At present, the different growth methods employed have not allowed to grow the materials in such a way as to explore continuously the dimensionality effects from bulk material to 0D nanostructures. Such studies require metrological control of the growth of the materials at the atomic layer scale in all three spatial directions.

With this in mind, researchers from IEMN in collaboration with a team from the University of Ghent have shown that it is possible to obtain, by colloidal chemical synthesis processes, anisotropic CdSe nanoparticles, called NanoPlanets (NPLs), for which the electron confinement can be finely tuned in all 3 spatial directions. These NPLs exhibit strong quantum confinement depending on their thickness which is in the nanometer range and is controlled to the nearest atomic layer. The lateral dimensions can be varied from a few nanometers to a hundred nanometers which allows to modify the electron confinement and to study finite size effects. Tunneling microscopy studies have shown that, for NPLs with finite lateral dimensions smaller than 30 nm, the densities of electronic states show Van Hove singularities, characteristic of 1D materials, in very good quantitative agreement with theoretical calculations of strong bonds, and in clear contradiction with the paradigm widely accepted for a decade for NPLs, of a 2D density of state for electrons in the conduction band.

These first results published in Nanoletters1 pave the way towards an understanding of the electronic properties at the dimensional boundary, which is essential for the development of functional hetero-nanostructures that would use the inherent advantages of different dimensionalities to optimize performance.

Read more :

(1)       Peric, N.; Lambert, Y.; Singh, S.; Khan, A. H.; Vergel, N. A. F.; Deresmes, D.; Berthe, M.; Hens, Z.; Moreels, I.; Delerue, C.; Grandidier B.; Biadala L. Van Hove Singularities and Trap States in Two-Dimensional CdSe Nanoplatelets. Nano Lett. 2021, 21 (4), 1702–1708. https://doi.org/10.1021/acs.nanolett.0c04509.

louis.biadala@iemn.fr

Logo
Cité Scientifique
Avenue Henri Poincaré
CS 60069
59 652 Villeneuve d'Ascq Cedex, France
Tel : 03 20 19 79 79
CNRS Logo University of Lille Logo University Polytech Logo Junia Logo Centrale Lille Logo Renatech Logo RFnet Logo
Plan du site
© Copyright Service ECM et pôle SISR 2024
  • Production scientifique
  • Mentions légales
  • Politique de confidentialité
Faire défiler vers le haut
fr_FR
fr_FR
en_GB
Nous utilisons des cookies pour vous garantir la meilleure expérience sur notre site web. Si vous continuez à utiliser ce site, nous supposerons que vous en êtes satisfait.OKNonPolitique de confidentialité