Auto-organisation tridimensionnelle et propriétés optiques de multicouches de boîtes quantiques d'InAs/InP

InAs/InP quantum dots (QDs) have been proposed for application to quantum dot lasers emitting at 1.55 μm wavelength and to photodetectors for far infrared radiation (10-20 μm). Such QDs are generaly self-assembled in the Stranski-Krastanov growth mode (the islands are formed on a wetting layer (WL)). The performance of devices based on self-assembled QDs is mainly limited by their size inhomogeneity. However, it was observed that the stacking of multiple layers of self-assembled QDs improves the uniformity of the size and lateral distribution of the islands from one layer to another, through their three-dimensional (3D) self-organization. Two self-organization regimes have been observed: vertical alignment (the QDs grow one above the other) and anti-alignment (the QDs nucleate at lateral positions located between those of the previous layer). One can take advantage of the vertical alignment of islands to bring the QDs of the various planes close enough to induce electronic coupling between them. As a result, radiative recombination occurs in the larger islands, which leads to a reduction of the QD-size dispersion participating in the emission. In this thesis, we study the growth of InAs(P)/InP(001) multilayers and the impact of their structure (spacer layer thickness, surface density, and island size) on the self-organization of the QDs and their optical properties. In particular, we have found a new strategy to obtain a large variety of island sizes and densities by perturbing the growth kinetics. We have also found a simple criterion to control the type of organization obtained. Finally, we have shown that the charge carriers are not transferred efficiently from the WL to the larger QDs and that the excitation of holes to the second heavy-hole levels is the dominant activated process leading to non-radiative recombination. The samples were grown by metalorganic vapor phase epitaxy. Since the morphology of the first deposited layer of islands influences the type of 3D organization obtained, we have first found the growth conditions allowing the drastic variation of the island size and areal density of uncapped samples. However, there is a strong correlation between these two parameters for selfassembled nanostructures, regardless of the growth parameters used (organometallic precursor flows, temperature, growth rate, etc.), since the morphology is mainly controlled by the growth kinetics: the density decreases as the size increases. However, we have found that the presence of oxygen traces in the reactor disturbs the kinetics of atoms on the growth surface in a unique way,