Electrochromic properties of rhodium oxide films prepared by a sol–gel method

Abstract Rhodium oxide films prepared by sol–gel method exhibit reversible two-color (bright yellow–olive green) electrochromic behavior. The X-ray diffraction analysis and scanning electron microscopy morphology observation suggest that these films are nanocrystalline materials. A significant difference of transmittance for the films at two different color states was observed. The color efficiency at 700 nm was 29.1 cm 2 C −1 . The electrochemical behavior of rhodium oxide electrode was measured by using voltammetry method, and the diffusion coefficient of 3.26×10 −14 cm 2 s −1 was determined. The great transmission difference in the visible region at different potential suggests that this film can be used in electrochromic devices.