Preparation and Properties of ZnO/ZAO Double-Layers Thin Films on the Substrate of Glass

Abstract

Aluminium zinc oxide(ZAO) thin films were deposited on soda-Lime-Silica glass substrate by middle frequency power magnetron sputtering. Then zinc oxide(ZnO) thin films were deposited above ZAO thin films by electrochemical deposition method at different time. ZAO thin films and ZnO/ZAO double-Layers thin films were characterized by X-Ray diffraction(XRD) and scanning electron microscope(SEM). A four-Point probe was used to determine the resistivity of the films. The optical transmittance of ZAO films and ZnO/ZAO films was measured by UV-Visible spectrum. The results represent that the transmittance of ZAO/ZnO thin films decreases gradually with deposition time increasing. When the deposition time is 5 minutes, the maximum transmittance of ZnO/ZAO films reaches to 85% at wave length from 400nm to 600nm, and the thickness and resistivity of thin film are 610nm and 2.04×10-3Ω•cm, respectively. However, the thickness and resistivity are highest when the deposition time is 20 minutes, which reaches to 808nm and 1.2×10-2Ω•cm. Meanwhile, the lattice constants a and c of ZAO/ZnO thin films demonstrate an expansion with deposition time increasing. In essence, good-Quality double-Layers thin films of ZnO/ZAO play an important role in CIGS solar cells.