Electrochromic Characteristics of Polyaniline and Poly(3-Methylthiophene) Thin Films for Display

Abstract

In this study, the polyaniline (PANI) and the poly(3-methylthiophene) (PMeT) of the conductive polymer electrochromic thin films had been deposited on the indium tin oxide/glass (ITO/Glass) substrate by electrochemical polymerization, respectively. The cycling stability of the electrochromic thin film prepared with the variety of the different charge densities was investigated. The electrochromic behaviors of the PMeT/ITO/Glass and PANI/ITO/Glass were performed in the electrolytes of 0.1 M lithium perchlorate (LiClO4)/propylene carbonate (PC) and 0.1 M LiClO4+0.001 M perchloric acid (HClO4)/PC, respectively. The colors of the PMeT thin film exhibited blue and red in oxidation and reduction states, respectively. And the colors of the PANI thin film exhibited green and yellow in oxidation and reduction states, respectively. Furthermore, the absorbance and transmittance (T%) of the electrochromic thin film were measured by ultraviolet-visible (UV-Visible) spectrometer in this study. Besides, in order to find the optimal manufacture conditions of the electrochromic thin film, the potentials of redox reaction and cycles were investigated by the cyclic voltammetry (CV) measurement system to analyze the cycling stability of the electrochromic thin film with the variety of the different charge densities. Finally, the reflectance (R%) of the optimal parameters of the electrochromic thin film was measured by chroma meter in this study. And the variational colors of the electrochromic thin film were observed by the chromaticity coordinates of the Commission Internationale de l'Eclairage (CIE), so that the electrochromic thin film can be applied to the filed of display.