Electrochemical, Optical and Electronic Properties of Iridium Tin Oxide Thin Film as Counter Electrode of Electrochromic Device

Iridium tin oxide films (IRTOFs) containing dispersed iridium oxide in a tin oxide matrix were prepared by an ion-plating process. The optical, electrochemical, and electronic properties of the films were measured by varying the iridium concentration in the films. The cyclic voltammogram characteristic of the films showed good reproducibility. The coloration efficiency of the IRTOFs increased with an increase in the concentration of iridium. The change ranges of the conductivity become more than $10^{8}$ times. The activation energy increased with increasing iridium concentration in the iridium concentration range in which the conductivity decreased. The characteristics of an all-solid-state electrochromic device with an IRTOF counter electrode were measured.