Small‐Signal A‐C Response Theory for Electrochromic Thin Films

Abstract

The identification and characterization of the pro-cesses responsible for the electrochromic properties of thin transition metal oxide films are matters of high current interest. Several authors (1-3) have applied small-signal a-c techniques in this area. Ho et al. (2) have analyzed their a-c data on WO3 with injected Li using the standard Randles (4) equivalent circuit, but with a modified (finite length) Warburg element. Gla-rum and Marshall (3) have devised a slightly different circuit from their data on IrO2 with injected protons. Both sets of authors have given some discussion of the theory underlying the use of these circuits. In a some-what earl ier paper (5) the present authors derived an equivalent circuit for an electrochemical system char-acterized by an electrode adsorption-reaction-diffusion