Silver (Ag) nanoparticles (NPs) were synthesized and used as an interfacial layer in the photoanode of quantum dot sensitized solar cells (QDSSCs). Two different methods were employed to determine the size and shape of the Ag NPs. Using transmission electron microscopy images and calculations based on Mie theory, a size of 5 nm and a spherical shape were obtained for the sensitized Ag NPs. Then these NPs were applied in a fluorine-doped tin oxide photoanode structure in the QDSSCs. As an interfacial layer, Ag NPs were dip-coated on FTO between an FTO glass and a layer. A successive ionic layer adsorption and reaction method was used for deposition of CdS quantum dots on the films. A power conversion efficiency of was obtained for cells, which was higher than found for noninterfacial layer cells. The easier transport of excited electrons and the inhibition of charge recombination due to the application of an Ag NPs layer are concluded to be responsible for the improved performance of the cells and their increased photocurrent.