Au Nanoparticle Sub-Monolayers Buried between Magnetron Oxide Thin Layers

Abstract

Abstract In this work, a versatile method to increase the optical response of the oxide nanostructures is proposed. It combines a magnetron deposition of oxide matrix with the thermal deposition and aggregation of metallic nanoparticles, allowing the preparation of wide band gap oxide heterostructures with buried plasmonic Au nanoparticles. Thin layers of Si/TiO2 and Si/NiO were deposited by reactive magnetron sputtering in a 2D nanostructure, followed by 2.5 nm gold layer thermal deposition and in N2 thermal annealing at 550 °C to induce the growth of the Au nanoparticles. Then Si/TiO2/AuNP and Si/NiO/AuNP were covered with TiO2 and NiO respectively. The reflectance maximum of the LSPR band appeared at around 700 ÷ 720 nm for both heterostructures. It was demonstrated that both Si/TiO2/AuNP/TiO2 and Si/NiO/AuNP/NiO heterostructures can enhance optical response in comparison with Si/TiO2 and Si/NiO. The results obtained indicate a broad prospect of using the formed structures in the field of integrated optoelectronic devices.