Electrochromic rhodium oxide films prepared by sol-gel method exhibited reversible two-color (bright yellow at reduction and dark green at oxidation) electrochromic behavior in alkaline solution with good cycle stability. The XRD, SEM, TG, DTA, UV-V, FTIR and voltammetry methods were used to study the structure and electrochromic properties of the films. It was found that the amorphous bright yellow rhodium oxide film formed via a heat treatment at 100 ℃ presented excellent electrochromic characteristics. Its electrochromic properties such as coloration efficiency, response time, cycle stability and open circuit memory were determined and a possible coloration mechanism of the rhodium oxide film was discussed.

Key words: SOL-GEL PROCESS, RHODIUM OXIDE, ELECTROCHROMISM, THIN FILMS, XRD, SEM