The effects of Polyvinylpyrrolidone on the Au sizes, dispersion and enhancement of absorption spectra of the nanoparticles Au/TiO₂ solutions for application in plasmonic solar cell

The nanoparticles Au/TiO₂ embedded system plays a very important role in the plasmonic solar cell. Recently the scientists have focused their research both on the theoretical and technological problems. One of research orientations is focused on optimizing the characterizations of Au/TiO₂ nanoparticles (NPs) for increasing efficiency of the plasmonic solar cell. This paper outlines the synthesis methods and some technological developments for preparation of the Au(10 %)/TiO₂ and Au(40 %)/TiO₂ solutions in the presence of polyvinylpyrrolidone (PVP) with different reaction rates of sodium borohydride adding into chemical reaction to control the Au NPs sizes, densities and dispersion of Au NPs being in Au/TiO₂ NPs solution aiming to make the suitable Au/TiO₂ thin film for application in plasmonic solar cell. The morphological, structural, absorption spectra of the Au/TiO₂ NPs solutions in the presence of PVP and without PVP are investigated by the HRTEM, EDX, XRD and UV–Vis spectroscopy techniques. Depending on the technological conditions, in presence of PVP, the synthesized Au NPs being in Au/TiO₂ solutions have their sizes are in range of 3–4 nm and of 8–10 nm with uniformly dispersed for the cases of slow reaction rate, and fast reaction rate, respectively, meanwhile the results of Au NPs synthesized without PVP which has different Au sizes, not uniformly dispersed. Based on experiment results the role and effects of PVP on controllable Au sizes, NPs densities and on the enhancement of the absorption spectra from peaks of 600 nm to the violet range are investigated and discussed.