The LEMTA (Laboratoire d’Energie et de Mécanique Théorique et Appliquée), Nancy, France, opens a position of postdoctoral fellow in the area of nanostructured thermoelectric (TE) materials. The work will be done in the frame of a French-Swiss collaborative project funded by the ANR-PRCI program and supported by LUE N4S. Topics of materials, thin films electrodeposition and multiscale modelling of TE composite materials are covered by this project.
Thermoelectricity has seen a renewed emphasis in the last decade due to significant advances in materials nano-fabrication processes with improved performances. This growing interest is reinforced by the fact that the solid-state thermoelectric (TE) devices can convert waste heat from sources such as power plants, motor vehicles, computers or human bodies to electric power using the Seebeck effect and then contribute to a sustainable development. Candidate materials have to exhibit large Seebeck coefficients, reduced thermal conductivity and high electrical conductivity. Over the past decade, most progresses in thermoelectric materials have been made by reducing lattice thermal conductivity through the surface and interfaces scattering of phonons of nanostructured materials. However, reducing device size to the nano-world (nanowire, nanofilms, etc.) has a main drawback which is the ability to use such devices in energy system designed at the macroscale. The goal of the current research project is to provide original solutions of new TE devices that combine the material efficiency observed at the nano into 3D materials based on hierarchically structured porous materials (see Fig. 1).
Objectives of the proposed work
Work program is divided in two stages. The first one will start at the beginning of the project and will aim to provide optimal design of micro-structure that could be suitable for the elaboration of efficient 3D thermoelectric materials. In this frame, two kinds of microstructures will be achieved for this research project using electrodeposition of TE materials on templates achieved by colloidal lithography (3DTEmat-CL) or two photons lithography (3DTEmat-2L).
In the case of 3DTEmat-CL the achieved structure is close to the one of open foam with very large porosity (f>90%) for which extensive literature exist concerning thermal transport. Thus, 3DTEmat-CL will be modeled using analytic relations that provide effective thermal conductivity according to the length and cross section of “ligaments” that links the “nodes” of the material. For 3DTEmat-2L (Fig. 1), investigations will be based on direct modeling by FEM of architecture micro-lattice using COMSOL. This modeling will take into account the thin film deposition of TE compounds on the polymer skeleton.
The second stage will last all along the project and will aim to evaluate through numerical simulations thermal transport in TE tin films and elaborated structures using models and tools developed during the first stage. In the present study Bi2Te3 and SnSe TE compounds are considered and an important part of the study will be to develop numerical tool for evaluating their thermal transport properties. Among them Monte Carlo method for the solution of the Boltzmann transport equation for phonon is in the core of the project.
Regular interactions with the material leaders (polymer structure elaboration and electrodeposition) of the project are expected as numerical simulations can help to understand and evaluate the thermal properties of the elaborated micro-lattices. Besides, other simulation approaches like molecular dynamics might be considered to describe thermal properties at the polymer/TE interface (Kapitza resistance).
Education / Competences / Strengths
Project leader: David Lacroix
This one-year position will be based at the LEMTA, 2 av. De la forêt de Haye, 54500 Vandoeuvre les Nancy. The duration cannot exceed 12 months.
The target start date for the position is September 2nd 2019, with some flexibility on the exact start date.
Applicants are requested to submit the following materials:
• A cover letter applying for the position
• Full CV and list of publications
• Academic transcripts (unofficial versions are fine)
Deadline for application is June 15th 2019. Applicants will be interviewed by an Ad Hoc Commission by Between June 15th and 30th.
Applications are only accepted through email. All document must be sent to email@example.com
Nancy, Lorraine, France
|Title||POSTDOCTORAL FELLOWSHIP - Modeling and numerical simulation of thermoelectric films|
|Employer||Lorraine Université d'Excellence (LUE)|
|Job location||34 Cours Léopold, 54000 Nancy|
|Published||April 3, 2019|
|Application deadline||June 15, 2019|
|Job types||Postdoc  |
|Fields||Nanotechnology,   Materials Chemistry,   Electrochemistry,   Polymer Chemistry,   Thermochemistry,   Materials Physics  |