Showing papers by "Claes-Göran Granqvist published in 1989"

Electrochromic Li(x)WO(3)/poymer laminate/Li(y)V(2)O(5) device: toward an all-solid-state smart window.

Abstract: We introduce a laminate two-layer approach to electrochromic smart windows. It incorporates two glass panes, each having a two-layer coating, laminated by a transparent adhesive solid polymer electrolyte. Each coating has a transparent conducting base layer (In2O3:Sn) and a top layer of an ion-insertion compound (based on WO3 or V2O5). The layers were made by evaporation or sputtering. Cyclic voltammetry in liquid electrolytes and spectrophotometry were used to characterize the layers. A novel electrolyte was developed: it comprised a methyl methacrylate network incorporating poly(propylene glycol) complexed with lithium perchlorate. Initial optical data are reported for laminated devices having an active electrochromic LixWO3 layer and a passive LiyV2O5 counter electrode.

An Electrochromic Window Based on Li x WO 3 / ( PEO ) 8LiClO4 / NiO

Abstract: Electrochromic materials are characterized by reversible but persistent changes of the optical properties when subjected to suitable electrochemical reactions. Electrochromism can be utilized in windows, most conveniently by exploiting all-solid-state multilayer coating backed by glass. The multilayer coating should comprise the following sequence of layers: a transparent and electrically conducting base layer, an electrochromic layer, and electrolyte, a conterelectrode, and a transparent conducting top layer. For window applications, the electrolyte should be transparent, and the conterelectrode must be either optically passive (colorless irrespective of its ionic content) or electrochromic in a sense that is complementary to the electrochromism of the electrochromic layer. The latter condition implies that if the electrochromic layer is cathodic (anodic), the counterelectrode must be anodic (cathodic). This paper reports preliminary data taken on samples with electrochromic layers based on tungsten oxide, WO{sub 3}, and nickel oxide, NiO, and an intermediate solid electrolyte of poly(ethylene oxide) doped with lithium perchlorate, (PEO){sub 8}LiClO{sub 4}, where 8 signifies the number of oxygen heteroatoms per lithium ion.

Angular Selective Window Coatings: Theory And Experiment

Abstract: Surface coatings with strongly angular-dependent transmittance are explored theoretically and experimentally. Theoretical studies are reported for multilayer coatings with more than one uniform metal film and for single-layer coatings with oblique columnar microstructure. The latter coatings are represented by effective medium theories encompassing prolate spheroidal structure elements. Amplitude coefficients for transmission and reflection are derived for the plane spanned by the column axis and the surface normal in uniaxial materials; these coefficients are extensions of well-known Fresnel relations. The transmittance of p-polarized light is angular selective, i.e. is unsymmetric around the surface normal, for absorbing columns. An experimental study of obliquely evaporated metal films showed that well defined inclined columns could be observed in scanning electron micrographs of fractured Cr films, and that the optical properties of such films displayed angular selectivity in qualitative agreement with theory.

Optical Materials Technology for Energy Efficiency and Solar Energy Conversion VIII

Abstract: This book covers the following topics: smart window coatings; Transparent infrared reflectors; Holographic concentrators and reflectors; Solar collecting devices; Solar absorber coatings; Optical properties and durability.

Towards An All-Solid-State Smart Window: Electrochromic Coatings And Polymer Ion Conductors

Abstract: We introduce a laminate two-layer approach to electrochromic smart windows. It incorporates two glass panes, each having a two-layer coating, laminated by a transparent adhesive solid polymer electrolyte. Each coating has a transparent conducting base layer and a top layer of an ion insertion compound. We made ion-insertion layers of W0 3 , V 2 0 5 and NiO x by sputtering and evaporation. These layers were characterized by cyclic voltammetry in liquid electrolytes and by spectrophotometry. Our novel electrolyte comprised a methyl methacrylate network incorporating poly (propylene glycol) complexed with lithium perchlorate. Initial optical data are reported for laminated devices having an "active" electrochromic Li x WO 3 layer and a "passive" Li x V 2 0 5 counter electrode.

Fractal structure of gas evaporated metal aggregates

Abstract: We analyze electron micrographs which show projections of three-dimensional fractal aggregates. Shadowing and finite size effects in the projection are treated by calculations for two model systems, namely a single and a connected aggregate. The calculations allow us to obtain the fractal dimension of the aggregates from the measured effective dimensions on the micrographs. Aggregates of metal particles were produced by gas evaporation and studied by electron microscopy. We measured the effective dimensions of the specimens and obtained the fractal dimensions from the connected aggregate model. The results are in good agreement with cluster-cluster aggregation models