Introduction of Ag nanoparticles and AZO layer to prepare AZO/Ag/FTO trilayer films with high overall photoelectric properties

Silver nanoparticles (Ag NPs) were prepared on commercial fluorine-doped tin oxide (FTO) glass by direct current (DC) magnetron sputtering and thermal annealing treatment. The effects of Ag layer thickness on the morphology of Ag NPs and performance of Ag/FTO bilayer films were investigated. The annealed Ag/FTO bilayer film with a 5 nm-thick Ag layer (Ag5/FTO bilayer film), which was covered with densely distributed 70-nm Ag NPs, possessed a sheet resistance of 5.7 Ω/sq that is lower than that of the FTO single-layer film (8.5 Ω/sq). The annealed Ag5/FTO bilayer film was selected for further optimization by coating it with sputtered aluminum-doped zinc oxide (AZO) layers. After thermal annealing, the AZO/Ag/FTO trilayer film with a 500 nm-thick AZO layer had a figure of merit of 2.97×10−2 Ω−1, which is more than double that of the FTO single-layer film (1.30×10−2 Ω−1). The results indicate that the introduction of Ag NPs and AZO layer can effectively improve the overall photoelectric property of FTO single-layer films.