Embedding plasmonic Au nanoparticles (Au NPs) into TiO₂ thin films enables visible-light harvesting through localized surface plasmon resonance (LSPR) and hot electron transfer to the semiconductor. The efficiency and lifetime of these carriers depend critically on the TiO₂ phase (anatase vs rutile), the density of oxygen vacancies (V₀/Ti³⁺), and the thermal stability of the nanostructure. The internship will focus on sputtered TiO₂ films with embedded Au NPs produced by pulsed laser ablation in liquids (PLAL). We will combine UV-Vis spectroscopy and femtosecond transient absorption spectroscopy (TAS) at various pump and probe wavelengths to quantify hot electron injection under plasmon excitation. Controlled annealing (air vs vacuum) will be used to tune defect density, while XPS and XRD will characterize oxygen vacancies and phase. Reference TiO₂ films without Au NPs will serve to isolate plasmonic contributions. This work will clarify the quantitative role of oxygen vacancies in hot electron injection and carrier dynamics in state-of-the-art PLAL-based nanocomposites.