36 mois

Black Silicon-based meta-materials: characterization of thermal and energy exchanges at interfaces

Heat management efforts aiming at controlling and reducing thermal losses in new electronic components require the development of new micro/nano-structured materials. This is the goal of this research.

Heat management efforts aiming at controlling and reducing thermal losses in new electronic components require the development of new micro/nano-structured materials whose properties such as thermal diffusivity, thermal effusivity or the interfacial thermal resistance/conductance can be controlled in order to improve the performance and reliability of systems. The aim is to improve the performance of electronic systems by intervening at the nano- and micrometric scales, where the levels of heat dissipation at these small scales can be extremely high. In addition, applications such a thermal energy harvesting or cooling also require energy management at the nanoscale. The development of appropriate experimental techniques6 is therefore essential to measure, understand and control the thermophysical properties of these new materials, as well as their couplings.

Black Silicon (BSi), the material at the heart of this thesis, is the result of a « bottom-up » structuring of silicon at the sub-micron scale on which the ESYCOM laboratory has been working for many years. In particular, due to its specific morphology, it is well known for its excellent absorption of almost 100% of incident visible light. BSi also has solar photothermal conversion properties and anti-reflective properties in both the visible and infrared spectra which can provide rectification possibilities in innovative systems for heat dissipation applications. Its fascinating optical properties allow it to be a privileged target for optimizing radiative heat transfer. It has also attracted attention in thermoelectricity. In addition, the original properties of this material can be controlled by varying several morphological (etching depth, aspect ratio of nanostructures) and electronic (doping) parameters in particular.

While the scientific literature has so far mainly focused on the optical properties of BSi, in this exploratory thesis we will focus on its thermophysical properties for heat management in electronic components. Two scientific and technological objectives should be addressed :

1) Fabrication and experimental characterization of new types of metamaterials,
2) Design of new systems benefiting from the meta-materials manufactured and characterized in phase 1,

More information is available in the job description pdf file available for download.

 

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