This thesis focuses on the aging of glass used in photovoltaic modules, a key challenge in the energy transition. High-power solar power plants operate at increasingly high voltages, which accelerates the migration of sodium from the glass into the cells—a phenomenon exacerbated by ambient humidity, known as potential-induced degradation (PID). This phenomenon limits the service life of the modules and restricts their use in medium- and high-voltage series installations. Recent studies show that adding other cations to the glass composition can reduce this migration, but the fundamental mechanisms of Na? ion transport remain poorly understood.
The objective of this thesis is to characterize these mechanisms in detail as a function of intrinsic parameters (composition, glass structure) and extrinsic parameters (voltage, humidity, temperature), first on the glass alone, then on modules fabricated with these glasses. The approach will combine experiments and modeling: preparation and physicochemical characterization of the glasses; high-temperature NMR (²³Na, ²?Si, ¹7O, ²7Al) to probe the local environments of the cations and activation energies; and molecular dynamics simulations (with and without an electric field, including on protonated systems) to study sodium mobility and directional ion transport.
The approach will follow a progressive increase in complexity: glass alone, then bifacial glass-encapsulant materials, and finally complete modules subjected to standardized aging tests used in the PV industry. We are seeking a candidate with a background in materials science, ideally with expertise in atomistic modeling. The dissertation will draw on collaborations between the CEA-Marcoule, INES (for module fabrication), CEA-Saclay, and CEMHTI (NMR), as well as Sorbonne University (simulation).