Study of zinc salt concentration effect on the growth of zno nanostructured oxides obtained by direct electrodeposition

Abstract

"Effect of zinc salt concentration on the growth of electrodeposited zinc oxide phases was investigated. ZnO thin films were elaborated via chronoamperometry on fluorine doped tin oxide (FTO) substrates from aqueous mixed bath of zinc nitrate and chlorate at 70°C. X ray diffraction patterns showed nanocrystalline films of hexagonal wurtzite phase with (101) preferential orientation for ZnO as grown in low concentration of Zn2+ salt. High concentration of Zn2+ favor the formation of Zn5(OH)8Cl2H2O simonkolleite phase. After heat treatment at 400 °C for 1h this later decomposes to ZnO oxide which presents no preferential orientation. The route mean square RMS roughness of surfaces estimated from AFM technique shows that ZnO generated from heat treated Zn5(OH)8Cl2H2O present more increasing roughness than ZnO deposits obtained at lower salt concentration. The photoelectrochemical answer indicated important generated photocurrents for both films which present n-type electrical conductivity"