PhD position, ab Initio Molecular Dynamic Simulations, INES, LOCIE, Chambéry, France (Deadline: 09.07.2025)

National Institute of Solar Energy (INES) – LOCIE Laboratory:  https://www.univ-smb.fr/locie/en/

Starting: october 1st 2025
Required: CV + Grades during Master year 1 and year 2
Skills in material sciences OR Energy OR Civil Engineering
Contact: christophe.menezo@univ-smb.fr // anna.lushnikova@univ-smb.fr

Context: In the context of climate change and the increasing frequency of heat waves amplified by the effects of urban heat islands, radiative cooling systems in buildings offer a promising technology, using the self-radiation and reflection of solar energy to provide efficient cooling without the need for energy consumption. Their installation on infrastructure elements such as roofs, facades, and canopies will reduce the rate of heat transfer to the interior of buildings, with a consequent reduction in carbon emission due to air conditioning in hot conditions, without representing a drawback in cold, sunny conditions . The spread of radiative cooling solutions and approaches will limit the use of critical raw materials or harmful refrigerants, with a cascade of positive economic and environmental impacts, and contribute to reducing the carbon footprint of cities.

Despite being discovered in the 1970s radiative cooling was primarily used for nighttime cooling at first due to the disparity between solar irradiance intensity and radiative cooling power during the day. For a body to cool down during the day through radiative processes, it must possess a high level of reflectivity in the solar spectrum (0.25-2.5 μm) and a high emissivity within the atmospheric window (8-13 μm) [5, 6]. Photonic crystals can manipulate spectra through dimensional variations, their large-scale manufacture is challenging because of the precision needed at the nanoscale. The additions of dielectric particles embedded in polymer materials seem more attractive for their capacity to achieve daytime radiative cooling and the possibility to be manufactured on a large scale and at low cost .

This also enables us to study a wide range of nanoparticles that can improve the macroscopic properties of these urban coatings. Indeed, several polar dielectric materials such as SiO2, TiO2, BaSO4, K2SO4, HfO2, … or hybrids including metallic nanoparticules interact with infrared electromagnetic waves through molecular vibrations. When illuminated by lights these materials absorb photons of specific frequencies, causing their molecules to vibrate and transition between energy levels. This process results in the absorption and the emission of photons at corresponding frequencies. In addition, some of these particles can impact the self-cleaning properties of the coating, which is important because various interferences can affect the cooling performance of the radiative cooling materials .

Materials and Methodology:
This PhD project proposes to investigate the contribution of nanoparticles using a molecular Ab-inito method.Ab-inito molecular dynamics simulations based on the density functional theory (DFT) succeeds in the accurate description of electronic, structural, and dynamic properties of a large variety of materials in different situations . Creating radiative cooling materials that are both enduring and resilient remains a challenge because of the lack of information about the processes that occur in polar dielectric materials at the atomic level. Only few studies have made attempts to consider complex crystals possessing radiative properties due to modeling at the atomic level.
However, the number of studies and structures remains limited, which does not allow to make clear the choice of one or another component in the cooling coating. To ensure the advancement of this field in the future, it is crucial to focus on developing new materials with highly efficient properties, particularly given the current climate conditions. Therefore, the main goal of this PhD thesis is to investigate the properties of polar dielectric materials at a molecular level, thereby enhancing our understanding of how they will behave within polymer materials on a macro scale. By conducting such research, we can gain insight into their performance under various circumstances. Moreover, this can also lead to numerous spin-offs in terms of manufacturing surface coatings for solar components, facade and roof coverings, in the form of paints, thin films, coatings, hybridization with building materials, etc.