Characterization and Stability of Electrochromic MoO3 Thin Films Prepared by Electrodeposition

Electrochemical, spectroscopic, and structural measurements were used to characterize the electrochromic behavior and stability of electrodeposited thin films. These films are prepared from metal/hydrogen peroxide solution on transparent conductive glass ( i.e. , ITO). The as‐deposited films are partially crystalline and show an improvement in crystallinity after heat‐treatment in air at 260°C. These films display reversible electrochromic properties from blue to clear, when cycled in a 1 M solution of lithium perchlorate in propylene carbonate between −0.5 and +2.5 V. The observed effects of heat‐treatment on the electrochromic properties are discussed and related to x‐ray photoelectron spectroscopy analysis. The elemental depth profiles of colored films were analyzed by secondary ion mass spectrometry.