Electrochromic nickel oxide films were deposited by radio-frequency magnetron sputtering of a Ni target in gas mixtures of Ar and O2. When electrochemically cycled in 0.1 N KOH solution, large reversible changes in visible absorption were obtained within the first 10 bleach/color cycles. Films which showed the greatest changes in optical properties and charge capacity were produced within a narrow range of oxygen flow rates. The coloration efficiency was found to be insensitive to the sputtering conditions and stoichiometry, with a value of 34+-4 cm2C-1 at 550 nm. This indicates that microstructure and charge capacity determine the absorption coefficient. The reaction rate was found to depend on the concentration of OH- in the electrolyte, indicating that OH- diffusion in the electrolyte limits the rate of reaction.
BT - Journal of Vacuum Science Technology A C1 -Windows and Daylighting Group
C2 - LBL-30066 DA - 02/1991 DO - 10.1116/1.577245 IS - 4 LA - eng M1 - 4 N2 -Electrochromic nickel oxide films were deposited by radio-frequency magnetron sputtering of a Ni target in gas mixtures of Ar and O2. When electrochemically cycled in 0.1 N KOH solution, large reversible changes in visible absorption were obtained within the first 10 bleach/color cycles. Films which showed the greatest changes in optical properties and charge capacity were produced within a narrow range of oxygen flow rates. The coloration efficiency was found to be insensitive to the sputtering conditions and stoichiometry, with a value of 34+-4 cm2C-1 at 550 nm. This indicates that microstructure and charge capacity determine the absorption coefficient. The reaction rate was found to depend on the concentration of OH- in the electrolyte, indicating that OH- diffusion in the electrolyte limits the rate of reaction.
PY - 1991 SP - 2170 EP - 2173 ST - J. Vac. Sci. Technol. A T2 - Journal of Vacuum Science Technology A TI - As-Sputtered Electrochromic Films of Nickel Oxide VL - 9 SN - 0734-2101 ER -