TY - JOUR T1 - Effect of Hydrogen Insertion on the Optical Properties of PD-Coated Magnesium Lanthanides JF - Electrochimica Acta Y1 - 1998/ A1 - Klaus von Rottkay A1 - Michael D. Rubin A1 - Franck Michalak A1 - Robert D. Armitage A1 - Thomas J. Richardson A1 - Jonathan L. Slack A1 - Peter A. Duine AB - Metallic magnesium lanthanide thin films upon insertion of hydrogen transform to a highly transparent hydride phase. With a Pd overlayer, the transformation can be produced either by electrochemical insertion of hydrogen or by exposing the film to hydrogen gas. Unlike amorphous oxide electrochromics, the transformation is accompanied by a large change in visible reflectance (about 50%). The optical switching effect in these materials is investigated in terms of changes in the complex refractive index as determined by variable-angle spectroscopic ellipsometric and normal-incidence radiometric measurements over the solar spectrum. Furthermore the optical effect of converting the Pd caplayer to Pd-H was determined. It is shown that the pd layer limits the visible transmittance of the hyrdrided stack to about 35-40%. Whereas the extinction coefficient of the dehydrided LnMg-layers at 550 nm is between 2.2 and 3.1, it is as low as 10-4 in the transparent state. CY - London, U.K. U1 -

Windows and Daylighting Group

U2 - LBNL-42277 ER - TY - JOUR T1 - Electrochromic Lithium Nickel Oxide Thin Films by RF-Sputtering from a LiNiO2 Target JF - Electrochimica Acta Y1 - 1998/ SP - 3085 EP - 3092 A1 - Franck Michalak A1 - Klaus von Rottkay A1 - Thomas J. Richardson A1 - Jonathan L. Slack A1 - Michael D. Rubin AB - Thin films of lithium nickel oxide were deposited by rf sputtering from a stoichiometric LiNiO2 target. The composition and structure of these films depended on the oxygen pressure during deposition (sputtering gas is Argon), and, to a certain extent, the target history. The sputtering geometry, i.e. the substrate to target distance and the sputtering angle were also critical. the films exhibit excellent reversibility in the potential range 1.1V to 3.8 V vs Li/Li+ and could be cycled in a liquid electrolyte half cell for more than 3000 cycles with a switching range ΔTvis close to 70%. The coloration efficiency in the visible was typically -30 to -40 cm2 C-1. The switching performance of a device utilizing a lithium nickel oxide film as counter electrode for a tungsten oxide electrochromic film is reported. VL - 44 U1 -

Windows and Daylighting Group

U2 - LBNL-42276 ER -