ThermAl nanoCOntactS – THACOS

Nanomaterials have multiple contacts and interfaces at the nanoscale where water molecules can be adsorbed and confined. These parameters can strongly modify heat dissipation in systems. However, thermal transport across nanoscale contacts is poorly documented. The project THACOS aims to fill the gap. Its objective is to understand better the involved physics. Heat transport will be studied for dry and wet nanocontacts for three hydrophilic materials, which are characterized respectively by a large phonon averaged mean free path (germanium), phonon-vibron transport (amorphous silica) or electron-phonon processes (gold). Moreover, as in nanocontacts, interfaces and contacts can be discontinuous at the atomic or nanometric scales, flat and rough surfaces will be considered. To reach THACOS’s objectives, advanced atomistic models and highly controlled experiments will be developed and unified. To go beyond the state of the art, the consortium will employ quantum non-equilibrium Green’s function in combination with ab-initio density functional theory calculations and classical molecular dynamics simulations to determine the thermal resistances at the investigated contacts. The central setup for experimental measurements of these thermal resistances to be compared with those from modelling will consist in a unique dual scanning electron and thermal microscopy instrument developed by partners. In the project, the setup will be optimized for 1- in-situ cleaning of the surfaces (Ar bombardment) before thermal measurement, 2- working under controlled water vapour pressure to form and destroy water meniscus and 3- managing the probe-sample contact by modifying the apex of commercial probes. New design bricks for the development of thermally optimised nanosystems are expected. For the success of the project, consortium gathers all the fundamental skills required, in modelling and experimentation, in physics and engineering.