Electron Trapping Enhancement in Gold and Silver Modified ZnO Nanocomposites as Photoanodes for Dye-Sensitized Solar Cells

Decorated ZnO nanoparticles were prepared with different ratios of gold and silver nanometals. The new nanocomposites minimized the charge recombination process by forming a Schottky barrier at the interface between ZnO and the noble metal(s) that acted as an electron sink. This phenomenon was obvious for ZnO/Au
₇₅
:Ag
₂₅
and ZnO/Au
₁₀₀
:Ag
₀
in which the electron-phonon interaction in the Au nanoparticles was slowed down and measured to be 3.87 ps for the former and 6.01 ps for the latter, compared to 2.50 ps for pristine Au nanoparticles. These materials should be useful as potential photoanodes for dye-sensitized solar cells, compared to unmodified ZnO.