The objective of the study is to investigate the electrochromic performances of layer-by-layer (LbL) multilayered
thin film electrode prepared from linear polyethylene imine (LPEI) and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) on PET-ITO substrate in the presence of different types of
electrolytes. For this purpose, the electrochromic behaviors of (LPEI/PEDOT:PSS)10 is performed in LiClO4/
propylene carbonate (PC) and two different ionic liquids (IL) namely N-methylimidazolium tetrafluoroborate
(Melm-BF4) and 2-hydroxy ethyl ammonium formate (2-HEAF), as a function of IL content and scanning rate.
The optical contrast value of (LPEI/PEDOT:PSS)10 film is determined as 58.4% in the existence of 10 wt% of 2-
HEAF as the electrolyte. The coloration efficiency of this film is determined as 606.7 cm2
/C, which this value
was greater approximately four times than 1 M LiClO4/PC. According to the obtained results, 2-HEAF has been
evaluated as a suitable electrolyte alternative for (LPEI/PEDOT:PSS)10 film due to its better optical contrast and
coloration efficiency compared to other electrolytes.