Electrochromic device for reversible color change in three different operating states

Abstract

Three-dimensional (3D) hierarchical ITO branches of electrochromic device (ECD) are an effective approach for increasing the optical properties by localized surface plasmon resonance compared to the two dimensional nanostructured electrodes. ECDs with the 3D branches were designed to operate in transparent, mirror, and black states. Finite-difference time-domain simulation was used to find, the electrical field distributions in three types of ECD: glass/ITO with Ag film, glass/ITO branches, and glass/ITO branches with Ag nano-particles. The ECDs had the optical transmittance of 73.76 % in the transparent state, the reflectance of 79.77 % in the mirror state, and the reflectance of 8.78 % in the black state. We achieved an ECD with high stability that can show ~10,000 switching cycles among the three states.