Electrochemical Proton Intercalation in Vanadium Pentoxide Thin Films and its Electrochromic Behavior in the near‐IR Region

This work examines the proton intercalation in vanadium pentoxide (V(2)O(5)) thin films and its optical properties in the near‐infrared (near‐IR) region. Samples were prepared via direct current magnetron sputter deposition and cyclic voltammetry was used to characterize the insertion and extraction behavior of protons in V(2)O(5) in a trifluoroacetic acid containing electrolyte. With the same setup chronopotentiometry was done to intercalate a well‐defined number of protons in the H(x)V(2)O(5) system in the range of x=0 and x=1. These films were characterized with optical reflectometry in the near‐IR region (between 700 and 1700 nm wavelength) and the refractive index n and extinction coefficient k were determined using cauchy’s dispersion model. The results show a clear correlation between proton concentration and n and k.