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

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 X 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. (C) 2001 Elsevier Science B.V. All rights reserved.