The electronic and optical properties of IZO thin films prepared by pulsed DC magnetron sputtering

The electrical and the optical properties of In₂O ₃-ZnO (IZO) films grown by using the pulsed dc magnetron sputtering method are investigated. We find that the average transmittance of the films in the visible range becomes over 85 % and that the optical band gap is about 3.3 eV, irrespective of the repetition frequency. The X-ray diffraction patterns for the film with a Zn content of 22 at.% show the crystalline structure to be amorphous. The growth rate and the sheet resistance of the film are shown to increase with increasing repetition frequency. Also, in a range of relatively thin thickness, the films grown with higher repetition frequency have higher refractive indices while, in the range of relatively thick thicknesses, the refractive index is nearly independent of the frequency.