The effect of Cu ions concentration on electrochromic properties of Cu embedded PANI thin films

Abstract

In this paper, copper salt (CuSO4.5H2O) has been used to improve electro-optical performances of PANI electrochromic layers including color switching rate (from transparent to colored state) and stability. For this purpose, the PANI solution was chemically prepared in the presence of different amounts (0.018, 0.03, 0.25, 0.5 and 2.5%w) of copper ions concentration by electrodeposition technique on a fluorine doped tin oxide (FTO) glass, which was used as a transparent conductive electrode and substrate. Finally, the five PANI/Cu samples were characterized and compared with pure PANI electrochromic layer. As a result, with cyclic voltammetry analysis and photospectroscopy, in the most optimal amount of copper (0.03%w) the optical contrast of the Cu embedded PANI electrochromic layer enhanced from 15% to 52.5%, its coloring time improved from 3 s to 1.3 s and its stability was the best.