Fabrication of a Co3O4/ZnO Heterostructure by Electrochemical Deposition

Abstract

Co3O4 thin films were fabricated using electrochemical deposition (ECD). Co(OH)2 precursor films were deposited galvanostatically from an aqueous solution containing Co(NO3)2 and NH4NO3, and subsequently converted to Co3O4 by annealing in the air ambient. The Co3O4 films had two absorption edges corresponding to energy levels of 1.5 and 2.0 eV, and exhibited a clear p-type photo response in the photoelectrochemical measurement. The pn heterostructures were fabricated with ZnO as the n-type partner. ZnO was first deposited using ECD, Co(OH)2 was subsequently deposited on it, and finally the sample was annealed. The fabricated Co3O4/ZnO structure exhibited clear rectification properties.