Formulation of organic electrode materials for Li-ion batteries with low environmental impact
This project delas with the development of Li-ion battery prototype with a capacity of 500mAh only based on the use of organic elecrode materials (PTCLi4 for the negative electrode and MgLi2pDHT for the positive electrode) combined with a polymer electrolyte developped by CNRS/LEPMI. It will focus on the issues related to material implementation in order to prepare électrodes containing low carbon ration (2mAh/cm2)
Polymeric reversible conductive adhesive for recyclable electronics
Electronic devices contain valuable and noxious metals that are today hardly recovered. While the demand for electronics is still growing, the urge for recyclable electronics development grows stronger. Printed Circuit Boards (PCB) are the core of electronics and contain electronic component that are fixed onto metal tracks through conductive adhesives. Such adhesives contain generally a metallic filler and a polymeric binder that is generally a polymerizable thermoset formulation.
With the increasing topics on material circularity, self-immolative polymers (SIP), polymer systems that have the ability to undergo depolymerization with a stimulus, have emerged in the recent years as viable systems to bring recyclability to polymer materials.
The current post-doc will develop a polymerizable SIP binder to be used in conductive adhesive in PCB applications. After the selection of adequate chemistries, the post-doc will synthesize SIP and evaluate their thermal and mechanical properties and their ability to depolymerize under stimulus. In a second step, the most promising SIP will be formulated as a conductive adhesive and will be applied to a PCB. The recyclability of the final object will be studied.
Development of piezoelectric resonators for power conversion
CEA-Leti has been working to improve energy conversion technologies for over 10 years. Our research focuses on designing more efficient and compact converters by leveraging GaN-based transistors, thereby setting new standards in terms of ultra-fast switching and energy loss reduction.
In the pursuit of continuous innovation, we are exploring innovative paths, including the integration of piezoelectric mechanical resonators. These emerging devices, capable of storing energy in the form of mechanical deformations, offer a promising perspective for increased energy density, particularly at high frequencies (>1 MHz). However, the presence of parasitic resonance modes impacts the overall efficiency of the system. Therefore, we are in need of an individual with skills in mechanics, especially in vibrational mechanics, to enhance these cleanroom-manufactured micromechanical resonators.
You will be welcomed in Grenoble within a team of engineers, researchers and doctoral students, dedicated to innovation for energy, which combines the skills of microelectronics and power systems from two CEA institutes, LETI and LITEN, close to the needs of the industry (http://www.leti-cea.fr/cea-tech/leti/Pages/recherche-appliquee/plateformes/electronique-puissance.aspx).
If you are a scientifically inclined mind, eager to tackle complex challenges, passionate about seeking innovative solutions, and ready to contribute at the forefront of technology, this position/project represents a unique opportunity. Join our team to help us push the boundaries of energy conversion.
References : http://scholar.google.fr/citations?hl=fr&user=s3xrrcgAAAAJ&view_op=list_works&sortby=pubdate
Development and application of TERS/TEPL technique for advanced characterization of materials
TERS/TEPL (Tip-Enhanced Raman Spectroscopy and Tip-Enhanced Photoluminescence) are powerful analytical techniques developed for nanoscale material characterization. The recent acquisition of a unique and versatile TERS/TEPL equipment at PFNC (Nano-characterization Platform) of CEA LETI opens up new horizons for materials characterization. This tool combines Raman spectroscopy, photoluminescence, and scanning probe microscopy. It features multi-wavelength capabilities (from UV to NIR), allowing a wide range of applications and providing unparalleled insights into the composition, structure, and mechanical/electrical properties of materials at nanoscale resolution. The current project aims to develop and accelerate the implementation of the TERS/TEPL techniques at PFNC to fully exploit its potential in diverse ongoing projects at CEA-Grenoble (LETI/LITEN/IRIG) and with its partners.
Modeling of charge noise in spin qubits
Thanks to strong partnerships between several research institutes, Grenoble is a pioneer in the development of future technologies based on spin qubits using manufacturing processes identical to those used in the silicon microelectronics industry. The spin of a qubit is often manipulated with alternating electrical (AC) signals through various spin-orbit coupling (SOC) mechanisms that couple it to electric fields. This also makes it sensitive to fluctuations in the qubit's electrical environment, which can lead to large qubit-to-qubit variability and charge noise. The charge noise in the spin qubit devices potentially comes from charging/discharging events within amorphous and defective materials (SiO2, Si3N4, etc.) and device interfaces. The objective of this postdoc is to improve the understanding of charge noise in spin qubit devices through simulations at different scales. This research work will be carried out using an ab initio type method and also through the use of the TB_Sim code, developed within the CEA-IRIG institute. This last one is able of describing very realistic qubit structures using strong atomic and multi-band k.p binding models.
Post-doc on 2D numerical simulation of perovskites/silicon heterojunction tandem solar cells
CEA-INES is looking for a post-doc to work on 2D simulation of perovskites/silicon heterojunction tandem solar cells. The candidate will have the responsibility to develop a model of the PK/SHJ tandem cell on the TCAD simulation package Silvaco. A realistic description of the materials will be implemented, based on in-house characterization of actual layers used (potentially performed during the post-doc), or based on literature. Then the focus will be set on the adjustment of the interface between the two sub-cells (so-called recombination junction, or tunnel junction). This model will afterwards be used to improve our understanding of the tandem cell working principle. In particular, inhomogeneity in layer properties, defects and there influence on cell efficiency will be investigated and brought face to face with experimental results. Finally, strategies to mitigate the influence of these defects will be defined to help the development teams to increase the device efficiency on large areas. For this post-doc position, the candidate needs solid background in semi-conductor physics, as well as previous record in working with simulation tools. He/She will need strong organization skills, and be willing to conduct theoretical work. The results will be published in peer-reviewed journals, as well as in conferences.
Post-Doc - Research Engineer In-situ characterization coupled with electro-reduction of CO2
This project concerns the Circular Carbon Economy program. It proposes mature solutions for industrial decarbonization based on electrochemical CO2 recovery. The candidate will be in charge of developing an electrolyzer for optimized conversion of CO2 into CO; a key molecule in the synthesis of many carbon-based products; by integrating in-situ characterization resources (UV-Vis, Infra-Red). The development of customized cells coupled with this local characterization, should enable to gain a better understanding of reaction phenomena, determine the diffusion mechanisms of species in the electrolytic medium, and extend the analysis to the entire electrochemical system. Studies and experiments will allow to optimize not only the catalytic system, but also the various cell components (membrane, electrode, Gas Diffusion Layer / Gas Diffusion Electrode, electrolyte, CO2 routing), in order to propose innovative, high-performance electrolyzer designs.
Calibration of the high dose rate flash therapy beam monitor of the IRAMIS facility
Ultra-flash beams are pulsed beams of high-energy electrons (over a hundred MeV) with pulse durations in the femto-second range. The IRAMIS facility (CEA Saclay) uses laser acceleration to produce this type of beam, with a view to their application in radiotherapy. The LNHB is in charge of establishing dosimetric traceability for the IRAMIS facility, and to do this it has to calibrate the facility's monitor. Current radiotherapy facilities are based on medical linear accelerators operating at energies of up to 18 MeV in electron mode. LNHB has such equipment. It is used to establish national references in terms of absorbed dose to water, under the conditions of the IAEA protocol TRS 398.
Establishing dosimetric traceability involves choosing the measurement conditions, knowing the transfer dosimeter characteristics used and any corrections to be applied to the measurements taking into account the differences between the IRAMIS Facility and those of LNHB.
Post-doctorate in PEM Fuel cells development and characterizations
The objective of this post-doctoral position is to understand how a realistic manufacturing defect in the Membrane Electrode Assembly (MEA) can affect the performance loss and the degradation rate of PEMFC stacks. Among the most common defects, the lack/absence of active layer (particularly at the anode side where loadings are very low), the presence of agglomerates, cracks or excessive thickness in the active layers or in the microporous level of the GDL are often encountered locally (few cm²). Here, this work will rely on the expertise at CEA LITEN to produce MEA with a controlled structure (homogeneous deposits, good membrane|electrode interface, mapping of local catalyst loading). Both homogeneous and defective MEA with controlled properties, will be tested electrochemically.
The tests will notably include clever coupling between the different physical and electrochemical characterization methods possible ex-situ, operando or post-mortem. Among them, magneto-tomography, a technique based on measuring the magnetic field generated by the current passing through the stack, will continue to be developed. These measurements will make it possible to quantify the 3D effect of defects during operation. Finally, the post-doctoral fellow will use existing modeling tools to improve the prediction of the lifespan of PEMFCs related to the initial local properties of MEA.
All these experimental and simulation works will make it possible to correlate local operational heterogeneities and the degradation mechanisms associated with the defects depending on their nature or their positioning in the cell. Consequently, this study will provide some key-recommendations for the type and size of defects acceptable within MEA in relation with the operating and lifespan specifications of the PEMFC system.
Modeling SiGe based spin qubits
The CEA is developing an original spin qubit platform based on "silicon-on-insulator" (SOI) technology and is now turning to new pathways in Si/SiGe (electrons) and Ge/SiGe (holes). This activity is carried out by a consortium bringing together three of major laboratories in Grenoble: CEA-IRIG, CEA-LETI and CNRS-Néel. On this SOI platform, Grenoble has, for example, demonstrated the electrical manipulation of a single electron spin, as well as the first hole spin qubit, and recently obtained record lifetimes and spin-photon coupling for hole spins. In this context, it is essential to support the development of these advanced quantum technologies with advanced theory and modeling. CEA-IRIG is actively developing TB_Sim code. TB_Sim is able of describing highly realistic qubit structures down to the atomic scale if needed, using atomistic strong bonding models and multi-band k.p models for the electronic structure of materials. Using TB_Sim, CEA has recently examined various aspects of spin qubit physics, in close collaboration with experimental groups in Grenoble and with CEA partners in Europe. The first objective of this research work is to strengthen our understanding of electron spin qubits based on Si/SiGe heterostructures through analytical modeling as well as advanced numerical simulation using TB_Sim. The second objective is to compare the performances of the Si/SiGe platform to other Ge/SiGe and Si MOS platforms to identify its strengths and weaknesses.