The fabrication of multicolor electrochromic device based on graphene conductive ink/poly(lactic acid) thin films by voltage-step method

Todays technology has significantly focused on advanced and smart materials. Electrochromism is a phenomenon wherein the change in optical properties of a material is induced byreversible redox process. Color change usually occurs between colored (darkened) state and transmissive (bleached) states or between two different colored states. In this research, we focused on silver (Ag) nanoparticles that exhibit various colors on the basis of their localized surface plasmon resonance (LSPR). The effects of step-voltage parameters on the coloration of the Ag deposition-based electrochromic device were investigated. Further, we report the use of graphene conductive ink (GCl)/poly(lactic acid) (PLA) as the transparent conductive electrode (TCE). Biopolymer film was coated with graphene ink by spin coating method. The samples were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometer (XRD), energy dispersive spectroscopy (EDS), electrical resistance measurements, cyclic voltammetry (CV) and ultraviolet-visible (UV-Ms) spectroscopy. Our results primarily indicate that the novel configuration (PLA/GCl/Ag/GCl/PLA) presents an easy and expeditious way of preparing the multicolor electrochromic device.