The physical and electrochromic properties of Prussian Blue thin films electrodeposited on ITO electrodes. (1st May 2019) - Isfahani, V. Bayzi
Abstract: In this article, a set of Prussian Blue (PB) thin films with different electrodeposition times (25 s, 50 s, 75 s, 100 s and 150 s) in air at ambient temperature was prepared. The layers were characterized by a variety of techniques which include, field effect scanning electron microscopy, energy-dispersive X-ray spectrometer, X-ray diffraction, Fourier transform infared spectroscopy, UV–Vis spectrophotometry, and electrochemical analysis. A simple and exact electrochemical method was used to estimate the optimal voltages for coloring and bleaching of different PB layers. Controlling electrodeposition time along with applying suitable voltage enabled us to investigate and improve electrochromic properties of PB layer. The sample prepared under 75 s deposition time showed probably a composition intermediate between the insoluble and soluble form. Furthermore, this sample (S75) shows a better electrochromic properties. High value of electrochromic contrast 55.36% at 555 nm and well stability of ion exchange by cycling are the characteristics of this layer. The control of the deposition time resulted in an increase of 9.38 times of the contrast ratio and corresponding values for optical density ( ΔOD) of the PB layers. Graphical abstract: Image 1 Highlights: PB thin films were prepared with CHA method at different electrodeposition times. Voltage for bleaching and coloring of electrochromic (EC) layers was proposed. Physical and EC properties of the layers were investigated. Controlling deposition time resulted in high EC contrast up to 76% in some cases. The prepared films are applicable for electrochromic devices.