INFLUENCE OF FILM PROCESSING TEMPERATURE ON THE ELECTROCHROMIC PROPERTIES OF ELECTRODEPOSITED NICKEL-HYDROXIDE

Nickel hydroxide thin film was deposited anodically from an aqueous so lution consisting of 10 mM of NiCl2 and 30 mM of (NH4)(2)SO4 at pH 8.5 and heat-treated at different temperatures. The effects of heat-treat ment on the electrochromic properties, colour/bleach durability cycle, response time and coloration efficiency, were investigated in a 0.1 M NaOH solution. A significant increase in the number of colour/bleach cycles from 100 cycles (for as-deposited films) to more than 5000 cycl es (for films heat-treated at 400 degrees C) was observed, while the a bsorbance decreased slightly at high temperatures. The change in elect rochromic behaviour at different temperatures is discussed based on th e electrochromic and thermal analysis.