In order to decarbonize energy production and meet climate plan objectives, the production of photovoltaic (PV) modules must increase significantly. To sustain these production levels, the silver content in latest-generation cells must be drastically reduced. Some alternatives incorporate less expensive metals (nickel, aluminum, copper) into screen-printing pastes. These approaches require evaluation in terms of contact formation, electron transport, and reliability. In a TOPCon cell architecture, the electrode must be brought into direct contact with the active layers of the cell via thermal annealing. This step enhances device performance (through a hydrogenation phenomenon) while simultaneously generating potential degradation related to the introduction of metallic species. This is especially critical when using new metals (Ni, Cu, etc.) with higher diffusivities than silver. The objectives of this thesis are manifold: to evaluate the performance of these low-silver alternative pastes once integrated into TOPCon cells; to characterize the impact of the introduction of these metallic species on the lifetime of photogenerated carriers in silicon; and to assess the long-term stability of these metallizations while verifying the absence of cell degradation phenomena under prolonged illumination. If necessary, an alternative metallization technique more suitable for these pastes will be developed. During the PhD, the successful candidate will be required to fabricate, metallize via screen printing, and characterize devices within a cleanroom environment.