ZnO:Ag and TZO:Ag Plasmonic Nanocomposite for Enhanced Dye Sensitized Solar Cell Performance

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. Short-circuit photocurrent density (J_sc) 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 (η) 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