The Nanoscale Heat Transport team (NHT-t) research activities are related to theoretical modeling, numerical simulation and experimental characterization of energy carriers (phonons & electron) transport properties in micro and nano-structures. NHT-team involves four permanent researchers.
The team is a part of Scientific Operation “Transport in Complex Media” within the LEMTA. Scientific objectives of the team are related to a better understanding of heat transport mechanisms while considering small space and time scales, i.e. beyond the applicability of Fourier’s law. Current research within NHT-team involves both theoretical and experimental approaches, which are tackled through the development of original numerical simulation tools and state-of-the-art experimental characterization devices. Those are:
- Ab-initio modeling and calculation of electron ad phonon transport properties of materials,
- Heat and mass transport in solids, fluids and at interfaces by means of Molecular Dynamic (EMD, NEMD, CgMD, …),
- Phonon heat transport in nano and micro-structured semiconductors solving the Boltzmann Transport Equation (BTE) with Monte Carlo techniques,
- Scanning Thermal Microscopy (SThM) for thermal properties characterization of micro and nano-devices (nanofilms, nanowires, nanoporous and nanoinclusions thin films, …),
- High frequency modulated thermoreflectance (FDTR) for non diffusive heat transport
Research and application fields explored by NHT-team are related to: new semiconductor materials for thermal management in microelectronic devices, nanostructured new thermoelectric materials, heat transport in micro and nano-devices, etc.
Projects et collaborations
NHT-team is involved in several scientific projects at national and European levels. Among them, there are: (ANR Mesophon, ANR RTG, ANR Spider-Man, and ANR-PRCI 3D Thermonano. Furthermore, team members are also very active in several research initiatives and network like: GDRe “Thermal NanoSciences and NanoEngineering Group”, EERA Joint Programme AMPEA
In what concerns collaborations, academic and industrial partners are (In France: C2N, Cethil, HotBlock Onboard, IEMN, IJL, Institut Néel, Institut Pprime, ILM, LOMA, ORANO ; in Europe and Worldwilde: Aristotle University Thessaloniki, Demokritos Institute, EMPA, Kyoto University, ICN2, LIMMS).
Figures caption
Figure 1 : Phonon lifetime and dispersion relations in silicon, DFT calculation; Thermal conductivity of diamond and hexagonal phases of silicon by Monte Carlo solution of BTE using DFT phonon lifetimes and dispersions.
Figure 2 : Aligned and staggered cylindrical pores in phononic membranes; SEM pictures and thermal conductivity calculation by resolution of the BTE with MC method, comparisons to experimental measurement (TDTR).
Figure 3 : (left) Scanning thermal microscopy principle. (right) Thermal imaging of Bi2Te3 nanowires (d=300nm).
Figure 4 : (left) High Frequency modulated thermoreflectance experimental apparatus. (right) FDTR principle.