Multi-Color states of High contrast Nano Prussian Yellow electro chromic film

Construction of electro chromic device via Prussian yellow Nano film on glass electrode. Energy conservation in one of the most primary research topics nowadays. Electro chromic device with low power consumption and short stable switching periods, are well suited to energy efficient applications, e.g. smart windows, car mirrors, displays, and electronic papers. Preparation of electro chromic nano Prussian yellow film on ITO glass by a simple chemical facile method and study of its electro chromic features Prussian yellow film (iron (III) hexacyanoferrate (III)), was prepared by immersing substrate in a solution of ferric nitrate and Potassium hexacyanoferrate. Prussian Yellow film was characterized by ultraviolet-visible (Uv-vis) spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy. Prussian yellow film, shows an intense yellow color when it is in pristine state. Resultant Prussian yellow film underwent reversible redox reactions accompanied with color changes from Prussian yellow to Prussian green to further Prussian blue then to Prussian white. Transmittance of Prussian yellow film varies from 21% for colored state at 450nm to 81 % (for fully bleached) at 0.9V. Contrast ratio and ratio of optical density to charge density were examined. The coloration efficiency was be calculated to be 299.6 cm2C-1. Prussian yellow can be very simply prepared and used as an efficient fast switching electro chromic device with high color contrast.