PhD Student (M/F) in Synthesis of thin films of chalcogenide perovskite (BaZrS₃ and derivatives) from nanopowders for photovoltaic and thermoelectric applications

Job Description

Thesis Subject

The scientific objective of this thesis is to develop new chalcogenide materials with a perovskite structure (particularly BaZrS₃ and substituted derivatives) in the form of thin films for optoelectronic applications, especially photovoltaic and potentially thermoelectric ones. These materials show strong potential for energy conversion due to their excellent solar spectrum absorption and promising charge transport properties.
The synthesis of these materials will begin with mechanochemical ball-milling to produce nanopowders with controlled stoichiometry and particle size distribution. These nanopowders will serve as precursors for thin-film deposition, enabling precise control over composition and microstructure.
Thin films will be fabricated using multiple deposition techniques, including electrophoretic deposition (EPD), spin-coating, and drop-casting, each offering distinct advantages in terms of film uniformity, thickness control, and scalability. Following deposition, the films will undergo post-deposition recrystallization under controlled chalcogen and/or metal halide fluxes. This step is critical for enhancing crystalline quality, reducing defects, and improving the electronic and optical properties of the films. The recrystallization process will be optimized to achieve grain growth and phase stability while maintaining compatibility with low-temperature conditions, a key requirement for industrial adoption.
A comprehensive characterization framework will be employed to establish structure-property relationships in the synthesized materials. Structural analysis will include X-ray diffraction (XRD) and Raman spectroscopy to confirm phase purity and crystallinity, while scanning electron microscopy (SEM) and atomic force microscopy (AFM) will provide insights into morphology and surface roughness. Optical properties, such as bandgap and absorption coefficients, will be determined using UV-Vis spectroscopy, while electronic properties, including carrier mobility, density, and Seebeck coefficient, will be measured through Hall effect measurements and thermoelectric characterization techniques. These data will be used to correlate chemical composition, synthesis conditions, and microstructure with the functional performance of the materials, providing a robust foundation for optimization.
To accelerate the discovery and optimization process, the project will leverage artificial intelligence (AI), specifically Bayesian optimization. This approach will enable the efficient exploration of a vast parameter space, including compositional variations, synthesis temperatures, deposition parameters, and recrystallization conditions. By iteratively refining the synthesis and processing conditions based on characterization results, Bayesian optimization will identify the most promising materials and processes that maximize photovoltaic efficiency, thermoelectric performance, and device stability. The integration of AI into the workflow will significantly reduce the time and resources required for materials development, aligning with the growing trend of AI-assisted materials discovery.

Your Work Environment

The Institut des Matériaux de Nantes Jean Rouxel (https://www.cnrs-imn.fr/) brings together more than 150 researchers and doctoral students. Through the design and characterization of new materials, the laboratory's approach aims to optimize a wide range of properties for applications such as photovoltaic cells, fuel cells, batteries for electric vehicles, nanotechnologies, and optical materials like LEDs. The MIOPS team, where the work will be conducted, specializes in the synthesis and characterization of inorganic and organic-inorganic hybrid materials with optical, optoelectronic, or magnetic properties.

Constraints and risks

Travel for meetings, conferences, and experiments will also be required.

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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