Bilayer TiO2:Ag/ZnO:Ag (TZO:Ag) oxide film is fabricated by using silver doped zinc oxide (ZnO:Ag) and
silver doped titanium dioxide (TiO2:Ag) nanopowder synthesized by sol–gel Technique. X-ray diffraction
(XRD) and UV-Visible spectroscopy (UV-Vis) results confirm the formation of TZO:Ag film. Band gap
energies are 2.96 eV, 2.99 eV and 3.02 eV for annealed TiO2:Ag, ZnO:Ag and TZO:Ag respectively. Shortcircuit
photocurrent density (Jsc) is increased from 0.106 mA/cm2 for the DSSCs with a single ZnO film to
0.495 mA/cm2 and 0.461 mA/cm2 for the DSSCs with a ZnO:Ag thin film and TZO:Ag thin film,
respectively. Efficiency (h) of DSSC has been improved to 345.71% and 351.428% with Ag doped ZnO and
ZTO film respectively as compared to undoped ZnO film. This improvement is attributed to the presence
of localized surface plasmon resonance (SPR) effect associated with spatially dispersed metallic Ag
nanoparticles on the surface of oxide nanoparticles, which enhances the light-harvesting efficiency and
promotes the separation of photogenerated electron-hole pairs.