Preparation of ITO Thin Films by Pulsed Laser Deposition for Use as Transparent Electrodes in Electrochromic Display Devices

Abstract

We deposited indium tin oxide (ITO) thin films by pulsed laser deposition (PLD) under various deposition conditions such as different levels of laser fluence and ambient oxygen gas pressure, while maintaining the substrate temperature at room temperature. We investigated the optical, structural, and electrical properties of the films as a function of the deposition conditions. We found that the variation of film properties is more dependent on oxygen gas pressure than on laser fluence. High quality ITO thin films with low electrical resistivity of 2-4 × 10 −4 Ω·cm and high optical transmittance of over 80% in the visible region are deposited on a glass substrate at room temperature under laser fluence above 4 J/cm 2 and oxygen gas pressure of 1 Pa. We experimentally produced an electrochromic device (ECD) using ITO coated glass substrate deposited at optimal deposition conditions. It is shown that ECD is colored by applied voltage and bleached when the voltage is reversed.