III-nitride quantum dots for application in opto-chemical sensors
type: Dataset
description: This thesis work has focused on the synthesis of (In)GaN-based quantum dot (QD) structures by plasma-assisted molecular-beam epitaxy (PAMBE), deposited in both polar (0001) and semipolar (11-22) crystallographic orientations, for application as optical transducers for chemical sensors for detection of pH levels, and hydrogen or hydrocarbon concentrations in gas or liquid environments. In the first part of this work, I describe the synthesis of semipolar-oriented two-dimensional layers: binary alloys (AlN, GaN and InN) and ternary alloys (AlGaN and InGaN), which are required for the reference contact of the transducers and set the basic know-how to understand the transition from two-dimensional growth to three-dimensional QD nanostructures. It is particularly relevant the study of indium kinetics and indium incorporation during the PAMBE growth of InGaN(11-22) layers. Similarly to (0001)-oriented InGaN, optimum growth conditions for this semipolar crystallographic orientation correspond to the stabilization of 2 ML of In on the growing InGaN surface, in excellent agreement with first-principles calculations. The limits of the growth window in terms of substrate temperature and In flux lie at same values for polar and semipolar materials. However, I observe an inhibition of the In incorporation in semipolar layers even for substrate temperatures below the segregation threshold for polar InGaN. In a second stage, I report the successful fabrication of superlattices (SLs) of GaN/AlN and InGaN/GaN QDs, both in polar and semipolar orientations. Photoluminescence and time-resolved photoluminescence confirmed the reduction of the internal electric field in the semipolar GaN/AlN QDs in comparison with polar structures. On the other hand, semipolar InGaN QDs must face the challenge of In incorporation in this crystallographic orientation. To overcome this problem, the influence of the growth temperature on the properties of the polar and semipolar InGaN QDs has been studied, …
landing page: https://theses.hal.science/tel-00870365
identifier: NNT: 2012GRENY028
keyword: boite-quantique
keyword: epitaxie-par-jets-moleculaires
keyword: infoeu-reposemanticsdoctoralthesis
keyword: molecular-beam-epitaxy
keyword: nanostructure
keyword: nitride
keyword: nitrure
keyword: optoelectronics
keyword: optoelectronique
keyword: physcondcm-genphysics-physicscondensed-matter-cond-matother-cond-matother
keyword: quantum-dot
keyword: semiconducteur
keyword: semiconductor
keyword: theses
issued: 2026-05-09T11:19:42.040859
modified: 2026-05-09T11:19:42.040863
language: fr
contact point: Organization
  fn: CCSD

test_moissonnage_selune
type: Agent

III-nitride quantum dots for application in opto-chemical sensors
type: Distribution
format: HTML
access URL: https://theses.hal.science/tel-00870365
issued: 2026-05-09T11:19:42.070674
modified: 2026-05-09T11:19:42.027495