Electrochromic Properties of Sol-gel NiO Films Dopped with Ti

Atheer Abu Yaqoup
Iyad Saadeddin
Ahed Zyoud
Hikmat S. Hilal

Electrochromic films of NiO & NixTi1-xO(2-x) (with Ti concentrations 5, 10, 15, 20, 25 & 30%) have been prepared by the sol-gel route using dip coating technique onto fluorine-doped tin oxide-coated glass substrates (FTO/glass). Ethanolic sols from nickel acetate tetrahydrate (Ni(CH3COO)2 • 4H2O) and titanium isopropoxide precursors were used in the preparations. The nano-sized films were sintered in air between 250 and 300°C. Characteristics of different films were studied in a comparative manner. Photoluminescence spectra, electrochromic behavior, cyclic voltammetry, XRD, thickness and SEM have been investigated. Typically, as the TiO2 content was increased, film characteristics were enhanced. Mechanisms of coloration and morphology transformation of the layer during cycling in 0.05 M KOH electrolyte were discussed in terms of an activation and degradation period. Calculation of cathodic charge (QC ), anodic charge (Qa), Optical density & Coloration efficiency were made. Our results indicate that electrochromic and other characteristics of the NiO can be enhanced by addition of TiO2 at certain concentrations.