Design Of Electrochromic Hybrid Poly(3-Methylthiophene)/Wo<inf>3</inf> Materials Via Electrochemical Route

Abstract

Poly(3-methylthiophene) (PMeT)/tungsten oxide (WO 3 hybrid films were fabricated by electropolymerization of MeT monomers onto WO 3 coated indium tin oxide (ITO) glass slides, which were prepared by electrodeposition technique. Hybrid films synthesized electrochemically in 1butyl-3-methylimidazolium tetrafluoroborate (BMIMBF 4 , 1butyl-3-methylimidazolium hexafluorophosphate (BMIMPF 6 , 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide (BMIMTFSI) and 1-butyl-1methylpyrrolidinium bis(trifluoromethylsulfonyl) imide (BMPTFSI) were applied to electrochromic device designs. Electrochromic characteristics of the devices such as optical modulation, coloration efficiency, switching time and stability were evaluated as the materials were switched between oxidized and reduced states. We fabricated electrochromic hybrid films consisting of WO 3 and that exhibited a large, stable, and reversible electrochromic modulations with an applied electrical potential. Highest optical modulation was observed as 57.92% for PMeT/WO 3 /BMIMTFSI hybrid film. The hybrid films also show stable electrochromism even after 1000 scans. The electrochemical, structural and morphological analyses of the fabricated films were performed by using Cyclic Voltammetry (CV), X-rays Diffraction (XRD) and Scanning Electron Microscopy (SEM). CV results revealed that PMeT /WO 3 hybrid films have much more electrochemical activity than those of WO 3 and polymer film1. In hybrid films, crystalline structures decreased compared to WO 3 , and more amorphous arrangements have been introduced2. The morphological properties of the hybrids changed depending on characteristics of ionic liquids.