%0 Conference Paper
%A Shi-Jie Wen
%A Klaus von Rottkay
%A Michael D Rubin
%B Electrochemical Society Meeting
%C San Antonio, TX
%D 1996
%G eng
%L LBNL-39593
%P 54-63
%T Electrochromic Lithium Nickel Oxide Thin Film by Pulsed Laser Deposition
%V 96-24
%1 <p>Windows and Daylighting Group</p>
%2 LBNL-39593
%8 10/1996
%X <p>Thin films of lithium nickel oxide were deposited by pulsed laser deposition (PLD) from targets of pressed LiNiO<sub>2</sub> powder with layered structure. The composition, structure and surface air sensitivity of these films were analyzed using a variety of techniques, such as nuclear reaction analysis, Rutherford backscattering spectrometry (RBS), x-ray diffraction, infrared spectroscopy, and atomic force microscopy. Optical properties were measured using a combination of variable angle spectroscopic ellipsometry and spectroradiometry. Crystalline structure, surface morphology and chemical composition of Li<sub>x</sub>Ni<sub>1-x</sub>O thin films depend strongly on deposition oxygen pressure, temperature as well as substrate target distance. The films produced at temperatures lower than 600 °C spontaneously absorb CO<sub>2</sub> and H<sub>2</sub>O at their surface once they are exposed to the air. The films deposited at 600 °C proved to be stable in air over a long period. Even when deposited at room temperature the PLD films are denser and more stable than sputtered films. RBS determined that the best electrochromic films had the stoichiometric composition Li<sub>0.5</sub>Ni<sub>0.5</sub>O when deposited at 60 mTorr O<sub>2</sub> pressure. Electrochemical tests show that the films exhibit excellent reversibility in the range 1.0 V to 3.4 V versus lithium and long cyclic life stability in a liquid electrolyte half cell. Electrochemical formatting which is used to develop electrochromism in other films and nickel oxide films is not needed for these stoichiometric films. The optical transmission range is almost 70% at 550 nm for 120 nm thick films.</p>