The high near-field enhancement occurring in the vicinity of metallic nanoparticles (MNPs) sustaining surface plasmons can only be fully exploited in photovoltaic devices if the MNPs are placed inside their semiconducting material, in the photoactive region. In this work an experimental procedure is studied to embed MNPs in gallium arsenide (GaAs) and silicon (Si), which can be applied to other semiconductor host materials. The approach consists in spin-coating colloidal MNPs dispersed in solution onto the substrate surface. Then a capping layer of the same material as the substrate is deposited on top to embed the MNPs in the semiconductor. The extinction spectra of silver (Ag) and gold (Au) MNPs embedded in GaAs and Si is modeled with Mie theory for comparison with optical measurements. This contribution constitutes the initial step towards the realization of quantum-dot intermediate band solar cells (QD-IBSC) with MN
