ZnO/Ta2O5 heterojunctions were formed on glass substrates using low temperature processes. Formerly insulating Ta2O5 films were deposited on glass substrates by vacuum evaporation using Ta2O5 powder, Afterwards transparent and conductive ZnO films were formed on the Ta2O5 films by thermal oxidation at 3200C in air atmosphere of zinc (Zn) films deposited by dc sputtering process. Structural and optical properties of ZnO were investigated by X-ray diffraction (XRD) and photoluminescence (PL). The Ta2O5 insulating films were characterized by Raman scattering. The ZnO/Ta2O5 heterojunction was characterized by current-voltage measurements at room temperature as well as transient response under a rectangular-pulse voltage source. The electrical and the transient response suggest that the ZnO/Ta2O5 heterojunction is a potential alternative for the fabrication of alternating-current-driven thin film electroluminescent (ACTFEL) devices.