Electrochromic and Ex Situ IR and Raman Spectroelectrochemical Studies of LiInVO Films Charged/Discharged in the 0 < x < 1 Domain

InVO films were prepared using the sol-gel route from V-oxoisopropoxide and In-nitrate precursors. Films were made by dip coating deposition technique which allows the preparation of films with a thickness up to 230 nm by a single dipping cycle. The structure of crystalline InVO films obtained at 500°C was investigated using Raman and IR spectroscopies, which were combined with X-ray diffraction. The crystalline films consist of a monoclinic InVO-I phase with an admixed orthorhombic InVO-III phase. Electrochemical investigations revealed that the charge capacity of the crystalline films (500°C) is about -40 mC cm, significantly exceeding the ion storage capacity of amorphous films prepared at 300°C (-20 mC cm). In situ UV-visible spectrolectrochemical studies of amorphous and crystalline films showed that the coloration of the films is cathodic with a change in a photopic transmittance (ΔT) from 0.034 to 0.149, respectively. Crystalline films exhibit higher coloring than amorphous films; this is related to their higher coloration efficiency (η = 1.92 cm C ). The main focus is given to IR and Raman spectroelectrochemical studies of crystalline InVO films (500°C) galvanostatically charged in the 0 < x < 1 domain (LiInVO). Vibrational spectra revealed that the monoclinic InVO-1 phase remains unchanged in the 0 < x < 0.44 domain and transforms to the amorphous phase when charged in the 0.5 < x < 1 domain. Vibrational band changes observed in Raman and IR spectra of charged and discharged films are assessed and correlated w ith the spectral features of CeVO, FeVO, and FeVO films studied previously. © 2001 The Electrochemical Society. [DOI: 10.1149/1.1369375] All rights reserved.