Electrophoretic deposition of plasmonic nanocomposite for the fabrication of dye-sensitized solar cells

Abstract

TiO₂-Ag nanocomposites have been prepared by hydrothermal process for the preparation of photoelectrode for dye-sensitized solar cells. The formation of TiO₂-Ag nanocomposites have been confirmed by the transmission electron microscopy (TEM), UV-Vis spectroscopy, X-ray diffraction and energy dispersive X-ray analysis. The TEM images confirm that silver nanoparticles of average size 30 nm are dispersed inside the TiO₂ matrix. Electrophoretic deposition technique (EPD) is successfully utilized to incorporate TiO₂-Ag nanocomposites in commercially available TiO₂ nanoparticle to prepare photoelectrode on transparent oxide substrate. Incorporation of TiO₂-Ag nanocomposites by EPD technique has been done in different ways: in all the layers of TiO₂ photoelectrode and in only the top layer of TiO₂ photoelectrode. X-ray diffraction, field effect scanning electron microscopy in back scattered mode and photoluminescence (PL) spectroscopy study confirm the presence of TiO₂-Ag nanostructure in prepared photoelectrode. The current-voltage characteristic shows 78% and 67% enhancement of photocurrent and power conversion efficiency (PCE) respectively in the DSSC with Ag incorporated photoelectrode compared to the cell without Ag nanoparticles and maximum PCE obtained in DSSC with TiO₂-Ag is 7.5%.