Offres de Post doctorat

Les offres:

 

Post doctorat atomic scale modelling scale of metal

Ingénieur Nano-matériaux

3D gate-all-around transistors based on vertical III-V nanowires for ultimate nanoelectronics

Optimisation d’oscillateurs opto-électroniques couplés/Optimization of coupled opto-electronic oscillators

 

 

 

 

 

Optimisation d’oscillateurs opto-électroniques couplés

Optimization of coupled opto-electronic oscillators

Equipe MOST

Micro-ondes et Opto-micro-ondes pour systèmes de Télécommunications

 

Responsables du contrat : Olivier LLOPIS olivier.llopis@laas.fr

Arnaud FERNANDEZ afernand@laas.fr

 

Mots clefs : optique-micro-ondes, lasers à modes verrouillés, oscillateur micro-onde, optique fibrée, bruit de phase, peignes de fréquence optique, ondes millimétriques

 

Le LAAS est impliqué actuellement sur l’étude d’un système de génération de signaux micro-ondes et millimétriques utilisant un laser fibré à modes verrouillés. Il s’agit plus précisément d’une approche COEO (Coupled Opto-Electronic Oscillator), c’est-à-dire du couplage d’un oscillateur micro-onde et d’un oscillateur optique qui partagent le même résonateur (optique). L’objectif de ce séjour post-doctoral est double : d’une part valoriser et améliorer les performances du COEO 10 GHz développé au LAAS, et assurer son transfert vers notre partenaire industriel local OSAT et, d’autre part, de monter en fréquence en gamme millimétrique à partir d’un deuxième dispositif utilisant une fréquence fondamentale à 30 GHz et susceptible de générer des harmoniques bien au-delà de 100 GHz. Dans un premier temps, on étudiera en particulier des moyens d’accorder la fréquence RF de sortie du COEO et de réduire l’effet des vibrations sur les composants fibrés (bobines de fibre en particulier). Ce premier travail rentre dans le cadre d’un contrat Aerosat et a un objectif proche de la problématique industrielle et de la commercialisation à court-terme du système. Le deuxième objectif, soutenu par un contrat ANR-défense, suppose des approches de modélisation & expérimentation plus risquées. Le contrôle du peigne optique généré par le COEO, l’optimisation de son battement vers 100 GHz et l’optimisation de son bruit de phase font partie de ces objectifs.

Cette étude étant soutenue par deux actions contractuelles différentes, la durée du séjour post-doctoral proposée est de deux ans.

 

Key words: microwave optics, mode locked lasers, microwave oscillator, fiber optics, phase noise, optical frequency comb, millimeter waves

 

LAAS is today involved in investigating a system for the microwave generation with optics based on a mode-locked laser. More precisely, it is a COEO (Coupled Opto-Electronic Oscillator), in which a microwave oscillator is coupled to an optical oscillator, both oscillators sharing the same resonator (optical). The goal of this post-doctoral position is twofold: firstly to improve the performance of an already realized 10 GHz COEO and to transfer the device towards an industry partner (OSAT) and, secondly, to increase the output frequency of the COEO above 100 GHz using the system nonlinearities and, probably, a fundamental frequency of 30 GHz in place of 10 GHz. In a first step, the investigations will focus on the frequency control of the 10 GHz COEO, together with the improvement of its sensitivity to vibrations (and particularly of the fiber spool). This first step is part of an Aerosat contract, and close to the industry requirements. In a second step, the millimeter wave device will be studied, with a focus on the optical comb and a possible RF output at about 100 GHz. This work is part of an ANR contract supported by the French ministry of defense.

Because of these two different topics, the proposed post-doctoral position will be a two years contract.

 

 

 

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3D gate-all-around transistors based on vertical III-V nanowires for ultimate nanoelectronics

Duration: 18 months

LAAS – CNRS, Toulouse

Contact : guilhem.larrieu@laas.fr

 

The position is open for 18 months (with possible extension) and will start as soon as the position will be filled.

Context: Semiconductor nanowires have quickly attracted the interest of the scientific community thanks to their remarkable properties in terms of elastic relaxation, transport, electronic or optical confinement. For electronics, the gate-all-around nanowire device is the ideal case for the electrostatic control of inversion charge and thus an excellent candidate for ultimate transistors. Vertical integration is a particularly attractive approach because of its extreme density integration (NWs arrays) and low cost fabrication method (no critical masks). Furthermore, it is directly compatible with synthesized NWs.

The goal of the work is to demonstrate transistor architectures based on vertical nanowire arrays (Nanoscale, 2013, 5, p. 2437) for low power nanoelectronic applications. These architectures will be integrated on III-V nanowires, which exhibit high carrier’s mobilities, implemented on a silicon platform. The activities cover a broad research spectrum from the material to the device level. The final device is 3D gate-all-around transistors implemented on these III-V NWs with a nanoscale gate length (sub 10 nm). The candidate will work on the nanofabrication of the device and its electrical characterization. She/he will interact with other members of the group working on this topic.

Environment: The candidate will work in a state of the art cleanroom environment and will have access to the micro &nanofabrication platform (1500m²) and characterization platform of the LAAS laboratory.

Candidate profile: The candidate must be a recent PhD graduate (within the last three years). Successful demonstrations of nanofabrication in a clean room environment are mandatory. Experience in advanced electrical characterization of nanoscale MOS transistors is a plus. Communication in French and/or English is required.

 

Contacts

CV, motivation letter and recommendation letter should be sent to

Guilhem Larrieu : guilhem.larrieu@laas.fr

 

 

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Postdoctoral position: atomic scale modelling of metal/metal oxide interfaces

Duration: 18 months

LAAS – CNRS, Toulouse

Contact : aesteve@laas.fr

A full-time postdoctoral research position is available in the LAAS-NEO research team at LAAS-CNRS, Toulouse. Within the project “chaire d’attractivité de l’université Fédérale de Toulouse - MUSE”, which aims at developing novel bottom-up engineering towards multifunctional & performance-tailored nano-materials, a two years position is opened for investigating fundamental aspects of the interface formation when processing metal/metal oxide nano-materials. The appointee will work in a highly multi-disciplinary framework composed of world-class chemists and physicists mixing competences in modeling/characterization and technology. A PhD degree in Physics, Materials Science, Chemistry or related disciplines is required. We seek for a motivated student with strong background in computational materials sciences, particularly in atomic scale modelling; skills in manipulating Density Functional Theory codes (either periodic or cluster packages) is mandatory. The applicant should send a detailed CV, including a list of publications and communications and a motivation letter to aesteve@laas.fr.

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Nano-material scientist 

Location: LAAS-CNRS, Toulouse, FRANCE

Duration: 18 months

LAAS-CNRS seeks for a self-motivated post-doctoral researcher to take in charge a French-US research project aimed at developing advanced nano-material for energy production applications.

The main goal is to explore how the interface chemistry of nanomaterials affects their thermal properties. This position will involve the synthesis of nanoscale thermite materials (e.g., Al/CuO nanolayers) including potential physico-chemical modifications of their interfaces. The candidate will interact with a larger group effort exploring advanced thin films and nanomaterials for energy production applications, with a particular emphasis on controlling the physical structure and interface chemistry of Al/CuO nanolaminates to develop a better understanding of the fundamental structure-property relationships  of such materials. The collaborative environment requires a candidate who has the ability to work as part of a team with scientists coming from different disciplines and to learn topics outside his area of expertise. The position will involve a combination of nano fabrication (RIE, photolithography, PVD), advanced characterization (HR-TEM, XPS, DRX) as well thermal and electrical analysis to characterize accurately the energetic capabilities.

The candidate will be required to work temporary in clean room facilities and to follow safe work procedures, as well as to handle chemical waste properly and keep a clean, well-organized work environment.

Required Education and Experience:

Must be a recent PhD graduate (within the last three years).

The ideal candidate for this position should have a strong background in the following areas: (1) nanomaterial synthesis and manipulation; (2) physico-chemical modificaions of surfaces (e.g., nanocrystals, nanowires, thin films); and (3) nanoscale characterizing  nanomaterials and their surfaces. Although general expertise in nanotechnologies, chemical engineering and manipulation will be considered.

 

Preferred Qualifications Ph.D. in materials science & engineering, physics, mechanical/electrical engineering or related fields.

 

Contact:

For further information you can contact Carole Rossi, LAAS-CNRS, N2IS Group: Carole ROSSI

 

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