AIR AND VACUUM ANNEALING EFFECT ON THE HIGHLY CONDUCTING AND TRANSPARENT PROPERTIES OF THE UNDOPED ZINC OXIDE THIN FILMS PREPARED BY DC MAGNETRON SPUTTERING

Abstract

In this study, we aim to investigate the effect of zinc interstitials (Zni) and oxygen vacancies (VO) on the ZnO electrical conductivity. ZnO films were synthesized via DC magnetron sputtering process using pure Zn target in gases mixture of Ar/O2 = 80/17.5 sccm. In order to improve the optical and electrical prosperities, the obtained films were subjected to air and vacuum annealing treatment. Several techniques such as field emission scanning electron microscopy (FESEM), Grazing Incidence X-ray Diffraction (GIXRD), Raman spectroscopy, photoluminescence spectroscopy (PL) and UV-visible were used to study the influence of heat treatment on ZnO properties. Electrical conductivity of ZnO films was determined by measuring the sheet resistance and thickness of the films. As deposited and under vacuum annealing films showed a lower electrical resistivity of 2.72×10−3 and 1.17×10−2 Ωcm, respectively, due to the Zn-rich conditions. ZnO films under air treatment show a intensity decrease of (103) plane and an optical transmittance of 87 %.