Characteristics of indium-tin oxide thin films grown on flexible plastic substrates at room temperature
Journal
Journal of Physics and Chemistry of Solids
Journal Volume
69
Journal Issue
2-3
Pages
527-530
Date Issued
2008
Author(s)
Abstract
Transparent and conductive indium-tin oxide (ITO) thin films were deposited on polyethersulfone (PES) flexible plastic substrates by DC magnetron sputtering. The crystalline structure and optical-electric characteristics were investigated to achieve the optimum room-temperature growth conditions. The crystalline orientation and the surface morphology were characterized by X-ray diffraction (XRD) and the atomic force microscopy (AFM), respectively. The ITO/substrate interfaces were observed by scanning electron microscopy (SEM). In addition, the resistivity, the Hall effect, and the optical transmittance were measured to characterize the photo-electric properties of as grown films. It is found that the ITO films are epitaxially grown with the orientations 〈2 2 2〉, 〈4 0 0〉, and 〈4 4 0〉 perpendicular to the film plane. Moreover, the resistivity of thin film decreases with an increase in the (2 2 2) diffraction intensity. The obtained optimum growth conditions for the room-temperature deposition are: DC power=300 W, deposition pressure=2.0 mTorr, and the gas of Ar:O2=100:1. With the optimum conditions, the resistivity of 6.42×10-3 Ω cm, carrier concentration of 1.13×1019 cm-3, and transmittance of 85% for films grown on PES substrates are obtained. Comparing the results with those reported by other workers, we conclude that improved photo-electric properties of ITO films can be obtained by using the DC magnetron sputtering technique at room temperature. © 2007 Elsevier Ltd. All rights reserved.
Type
journal article