Skip to Main content Skip to Navigation
Theses

Propriétés structurales et optiques de nanostructures III-N semiconductrices à grand gap : nanofils d'AlxGa1-xN synthétisés par épitaxie par jets moléculaires et nanostructures de nitrure de bore.

A. Pierret 1, 2
2 NPSC - Nanophysique et Semiconducteurs
PHELIQS - PHotonique, ELectronique et Ingénierie QuantiqueS : DRF/IRIG/PHELIQS
Abstract : This work focuses on structural and optical properties of III-nitrides wide-band gap semiconductors (AlxGa1-xN et h-BN), emitting in the ultraviolet range (4-6 eV). Nano-objects properties being modified by dimensional reduction, this work was mostly focused on the study of nanostructures of these materials (AlN and AlxGa1-xN nanowires, BN nanotubes and nanosheets). Careful search for correlation between their structure and luminescence has also been carried out. Concerning AlxGa1-xN materials, nanowires have been grown by plasma-assisted molecular beam epitaxy. The use of GaN nanowires bases has allowed us to promote the growth of non-coalesced 1D AlxGa1-xN nanostructures. We have shown that the incorporation of gallium is very temperature-dependent, giving rise to nanowires made of a highly inhomogeneous alloy at several scales (from nanometer to a hundred nanometers). These inhomogeneities strongly influence the optical properties, dominated by localized states. Altogether these results allow us to propose a growth mechanism of these nanowires. Concerning BN materials, comparison of the properties of nanostructures with those of the bulk material (hexagonal BN) has been carried out. After that h-BN bulk has been further investigated, we have revealed that nanosheets with more than 6 monolayers present a luminescence similar to h-BN. This indicates a low influence of dimensional reduction in h-BN, contrary to the case of nanowires made of other nitrides. Finally we have shown that the main nanotubes investigated in this work, which are multiwall, have a complex structure that is micro-faceted, and that the defects are likely responsible of the observed luminescence.
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-01020119
Contributor : Alain Broc <>
Submitted on : Monday, July 7, 2014 - 5:18:05 PM
Last modification on : Tuesday, September 1, 2020 - 3:24:03 PM
Long-term archiving on: : Tuesday, October 7, 2014 - 4:57:15 PM

Identifiers

  • HAL Id : tel-01020119, version 1

Citation

A. Pierret. Propriétés structurales et optiques de nanostructures III-N semiconductrices à grand gap : nanofils d'AlxGa1-xN synthétisés par épitaxie par jets moléculaires et nanostructures de nitrure de bore.. Science des matériaux [cond-mat.mtrl-sci]. Université Pierre et Marie Curie - Paris VI, 2013. Français. ⟨tel-01020119⟩

Share

Metrics

Record views

605

Files downloads

338