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Last name: TOTTEREAU
First name: Olivier
International audience
International audience
Hypervelocity impacts are common in the solar system, in particular during its early phases when primitive bodies of contrasted composition collided. Whether these objects are chemically modified during the impact process, and by what kind of processes, e.g., chemical mixing or gas–liquid–solid fractionation, are still pending questions. To...
Silica-based fibers doped with LaF3 :Tm3+ nanoparticles, prepared by MCVD and solution doping exhibited a fluorescence lifetime of 55 μs at 810 and 1470 nm, with background losses below 0.1 dB/m at 1300 nm.
In this work, we describe the main features of selective area growth (SAG) of GaN by molecular beam epitaxy (MBE) using ammonia. Different schemes such as growth into micrometer and nanometer size windows in Si3N4 dielectric masks and mesa structures etched on GaN or Silicon substrate are studied.
Focused ion beam technique is a powerful tool for defining patterns within a semiconductor film. In this paper, we show that it is possible to realize patterns such as disks and columns within thick GaN templates and that it is compatible with the regrowth of GaN based heterostructures. We study the effect of the pattern size and shape on the...
National audience
Self-assembled AlyGa1%yN quantum dots (QDs), with y = 0 and 0.1, have been grown by molecular beam epitaxy on Al0.5Ga0.5N(0001) oriented layers using sapphire substrates. The QD formation has been followed in situ by reflection high energy electron diffraction (RHEED). A two- to three-dimensional (2D–3D) transition of the layer morphology is...