Study of semiconductors nanoemitters for quantum photonics: Microcavity polariton under two-photon excitation and single photon emission with colloidal nanocrystals.
type: Dataset
description: My thesis focused on the study of photons and electrons con nement in several systems. First, I studied a new type of semiconductor nanocrystals to get at room temperature, an e ficient source of single photons polarized. I developed also a technique for two-photon excitation of polaritons in semiconductor microcavities. Our semiconductor nanocrystals have the particularity to have an elongated shell in cadmium sulfi de (CdS) around a spherical core of cadmium selenide (CdSe). During the last decade, semiconductor nanocrystals are known to be effi cient single photons emitters at room temperature. Their photoluminescence present two defects : Blinking, which is the phenomenon of random switching between on and o ff states, and a very low polarization issue. In this work, acting on the geometric parameters of nanocrystals (diameter of the core and length of the shell) I got strongly polarized single photon emission (linear polarization ratio greater than 80%) and showed the link between polarization and the aspect ratio of the nanocrystals. In addition, nely adjusting the thickness of the shell, I have demonstrated the possibility to reduce strongly blinking, while retaining a single photon source with high quality (g(2) < 0:2). In the second part of my thesis, I am interested in strong light-matter coupling in semiconductor microcavities and micropillars. I have developed and characterized a new type of excitation of polaritons based on two-photon absorption. In the case of micropillars where polaritons are confi ned to a 0D system, we have demonstrated photon lasing with two-photon pumping. Relaxation and interactions between polaritons are also compared under di fferent excitation.
issued: 2026-05-11T07:03:37.907063
language: fr
modified: 2026-05-11T07:03:37.907068
contact point: Organization
  fn: CCSD
keyword: absorption-a-deux-photons
keyword: auger-recombination
keyword: bi-exciton
keyword: blinking
keyword: boite-quantique
keyword: clignotement
keyword: couplage-fort-lumiere-matiere
keyword: cryogenic-temperature
keyword: cryogenie
keyword: effet-laser
keyword: individual-nanocrystals
keyword: infoeu-reposemanticsdoctoralthesis
keyword: laser
keyword: microcavite-planaire
keyword: micropiliers
keyword: micropillars
keyword: nanocristaux-individuels
keyword: nanocristaux-semiconducteurs
keyword: physqphyphysics-physicsquantum-physics-quant-ph
keyword: planar-microcavities
keyword: polariton
keyword: quantum-dots
keyword: recombinaison-auger
keyword: semiconductors-nanocrystals
keyword: strong-light-mater-coupling
keyword: theses
keyword: trion
keyword: two-photon-absorption
landing page: https://theses.hal.science/tel-00818662

Study of semiconductors nanoemitters for quantum photonics: Microcavity polariton under two-photon excitation and single photon emission with colloidal nanocrystals.
type: Distribution
format: HTML
issued: 2026-05-11T07:03:37.941790
modified: 2026-05-11T07:03:37.863662
access URL: https://theses.hal.science/tel-00818662

test_moissonnage_selune
type: Agent