PhD: Suspended Fe2VAl thermoelectric micro-generators (M/F)

The proposed thesis will be conducted at the Institut NÉEL of CNRS in Grenoble within the TPS team (Thermodynamics and Biophysics of Small Systems). It is part of the IOTEGH project funded by the National Research Agency.

The Institut NÉEL is a CNRS unit (UPR 2940) under agreement with the University Grenoble Alpes. It is one of the largest French national research institutes for fundamental research in condensed matter physics enriched by interdisciplinary activities at the interfaces with chemistry, engineering and biology. It consists of 450 employees, including 175 researchers.
It is located in Grenoble, in the heart of a unique scientific, industrial and cultural environment, right next to the French Alpes.
The current team relies on numerous technological poles such as nanofabrication, cryogenics, optics, X-ray diffraction, which will be very useful for the characterization of thin layers and the construction and testing of thermoelectric microdevices. All common resources of the Institut NÉEL will be made available for the success of the project. Travel outside the region will occur during the thesis.

Wireless sensor networks can collect numerous parameters useful for monitoring industrial processes. However, their deployment is limited by difficulties related to sensor power supply. The IoTEGH project, which funds this thesis, proposes to develop planar thermoelectric nanogenerators (nanoTEGs) based on Heusler-type Fe-V-Al materials adapted to this application. These nanoTEGs could generate sufficient electrical power to supply connected sensors in a completely autonomous manner, without batteries or wires. The Neel Institute in collaboration with the startup MOÏZ, the project coordinator, is developing nanoTEGs using thin layers of Bi2Te3. While this material is standard for widespread use, the specifics of nanoTEG technology make it less suitable for this application. The resistance of thin layers of Bi2Te3 is too high for nanoTEGs to be implemented within a real device. To reduce this internal resistance, Bi2Te3 can be replaced by more conductive, more abundant, and less toxic Heusler-type Fe2VAl alloys. The objective of the thesis work is to optimize and characterize thin films of the Fe-V-Al family using a multicathode sputtering process for their integration onto suspended SiN membranes for nanoTEG development.

Expected skills:
- Holder of a master's degree (or equivalent) ensuring in-depth knowledge in materials science and materials for energy (particularly in thermoelectric materials)
- Strong aptitude for experimental sciences (synthesis and analysis)
- Organizational skills
- Ease of communication in English
- Knowledge in the field of thin-film thermoelectric devices will be a strength