Effect of the ZnO Buffer Layer Thickness on AZO Film Properties

To evaluate the influence of the ZnO buffer layer thickness on structural, electrical and optical properties of ZnO: Al (AZO)/ZnO bi-layer films, a series of AZO/ZnO films were deposited on the quartz substrates by electron beam evaporation. X-ray diffraction measurement shows that the crystal quality of the films is improved with the increase of the film thickness. The electrical properties results show that the resistivity decreases initial and then increases. However, optical transmittance of all the films is >80% regardless of the buffer layer thickness in the visible region. The results illustrate that the insertion of ZnO buffer layer can improve the film performance.