Fonctionne avec Indico
v3.2.8
10h: Zakariae En-Naji
New hybrid technology for thin film deposition of transparent conductive oxides for photovoltaic applications.
Enhancing the efficiency of photovoltaic (PV) cells is crucial for sustainable energy production. A particular attention needs to be given to the deposition of transparent conductive oxides (TCO), which constitute the electrodes of many solar cell technologies. However, the current deposition technique for TCOs using magnetron sputtering (MS) presents challenges due to its energetic species which can degrade the performance of the PV cell layers.
My thesis project explores novel patented Hybrid Plasma Deposition (HPD) technique aimed at minimizing energetic bombardment during TCO deposition, thereby improving PV conversion efficiency. The project endeavors to refine the technique through modeling and experimentation. The objectives of my thesis are to optimize the energy and thermal efficiency of the active system composed of an evaporator integrated into a unitary plasma source. The discharge performances will be thoroughly examined in correlation with the TCO films deposited on various substrates. The ultimate goal is to establish a deposition process for TCOs using the HPD technique which will subsequently be transferred into industrial photovoltaic cells.
10h30: Manon Ramel
Impact of blending on weak lensing measurements with Rubin/LSST
According to the Lambda CDM standard cosmological model, 95% of the Universe remains unknown as it consists of two poorly understood components: dark matter and dark energy. Galaxy clusters, the largest gravitationally bound structures in the Universe, are sensitive to these components, making them powerful astrophysical objects that we observe to refine our theoretical cosmological models. They can be studied through their abundance, which depends on their masses. The masses of galaxy clusters can be estimated by observing the distortions they induce in the shapes of background galaxies, known as weak gravitational lensing effects.
To measure these distortions, upcoming deep optical surveys, such as the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST), will scan the sky to unprecedented depths, detecting billions of galaxies. This amount of detections will however cause the apparent superposition of galaxies on the images, called blending, thereby impacting the measurements of individual galaxy properties such as their shapes. Consequently, this could also impact the weak lensing measurements induced by galaxy clusters and the estimated masses derived from them.
This presentation will address the issue of blending in cosmology within the framework of the international Dark Energy Science Collaboration (DESC) of LSST. To identify and characterize blended galaxies in simulated LSST data, I have developed a matching algorithm called "friendly," which employs a novel approach combining multiple matching procedures along with a probabilistic method. I will demonstrate the performance of this new algorithm in detecting blended galaxies using simulated data. As a result, it was found that 27% of the galaxies could be affected by this systematic effect, potentially leading to biased measurements of the shapes of background galaxies, which are crucial for determining the masses of large-scale structures through weak lensing.