Photoluminescence enhancement and quenching of Sm, Au Co-doped TiO ₂

In this study, a novel hybrid nanostructure for enhancing photoluminescence (PL) was prepared by doping samarium (Sm) and gold (Au) into titania (TiO ₂:Sm³⁺:Au) via a simple sol-gel method. The X-ray diffraction and PL results indicate that the sample with better crystallinity has better emitting performance. The dependence of the PL intensity was examined as a function of the concentration of Au nanoparticles (NPs) while keeping the Sm content constant at 2%. It is found that PL enhancement and quenching can be obtained by tuning the content of Au NPs. The PL results suggest that the PL emission of this hybrid system relies on the energy (emitting light) transferred from TiO₂:Sm³⁺ to Au NPs. The plasmon state around Au NPs can be excited to bring out PL enhancement only when the intensity of the transferred energy meets the requirement of Au NPs.