Showing papers on "Electrochromism published in 1995"

Handbook of inorganic electrochromic materials

Abstract: Part 1 Case study on tungsten oxide: bulk crystalline tungsten oxide tungsten oxide films - preparation, structure, and composition of evaporated films tungsten oxide films - preparation, structure, and composition of sputter-deposited films tungsten oxide films - preparation, structure, and composition of electrochemically and chemically prepared films tungsten oxide films - ion intercalation/deintercalation studied by electrochemical techniques tungsten oxide films - ion intercalation/deintercalation studied by physical techniques tungsten oxide films -ultraviolet absorption and semiconductor bandgap tungsten oxide films - optical properties in the luminous and near-infrared range tungsten oxide films - theoretical models for the optical properties tungsten oxide films - electrical properties. Part 2 Electrochromism among the oxides (except tungsten oxide): molybdenum oxide films miscellaneous tungsten- and molybdenum-oxide-containing films iridium oxide films titanium oxide films manganese oxide films vanadium dioxide films vanadium pentoxide films nickel oxide films cobalt oxide films niobium oxide films miscellaneous oxide films systematics for the electrochromism in transition metal oxides inorganic non-oxide electrochromic materials. Part 3 Electrochromic devices: transparent electrical conductors electrolytes and ion conductors ion storage materials - brief overview devices with liquid electrolytes devices with solid inorganic electrolytes and ion conductors devices with polymer electrolytes time-dependent device performance - a unified treatment.

Electrochromism : fundamentals and applications

Abstract: Part 1 Introduction: electrochromism - what is electrochromism?, existing technologies, electrochromic displays and shutters, terminology of electrochromism, primary and secondary electrochromism, colour and contrast ratio, colouration efficiency, write-erase efficiency, response time, cycle life, the insertion coefficient, ECD appearance electrochromic systems -equilibrium electrochemistry, electrochromic operation exemplified, voltammetry, charge transfer and charge transport, AC or RF electrochemistry, electrodes construction of electrochromic devices -all-solid cells with reflective operation, all-solid cells with transmissive operation, solid electrolytes, the preparation of solid electrochromic films, liquid electrolytes, self-darkening electrochromic rearview mirror for cars employing type 1 (solution-phase) electrochromes. Part 2 Electrochromic systems: metal oxides-cobalt oxide, indium tin oxide, iridium oxide, molybdenum trioxide, nickel oxide, tungsten trioxide, vanadium pentoxide, other metal oxides, mixed metal oxides, metal oxide - organic mixtures phthalocyanine compounds - lutetium bis(phthalocyanine), other metal phthalocyanines, related species prussian blue - preparation of prussian blue thin films, prussian blue electrochromic films, prussian blue ECDs, prussian blue analogues other inorganic systems - deposition of metals, deposition of colloidal material, intercalation layers, inclusion and polymeric systems bipyridilium systems - bipyridilium redox chemistry, bipyridilium species for inclusion within ECDs, recent developments electroactive conducting polymers - polyaniline electrochromes, polypyrrole electrochromes, polythiophene electrochromes, poly(carbazole), miscellaneous polymeric electrochromes, recent developments other organic electrochromes - monomeric species, tethered electrochromic species, electrochromes immobilised by viscous solvents polyelectrochromism - studies of polyelectrochromic systems photoelectrochromism and electrochromic printing - device types, electrochromic printing or electrochromography.

Electrochromic mirrors and devices

Abstract: The present invention relates to electrochromic mirrors and devices whose electrochromic element is composed of an electrochromic solid film and an electrolyte comprising redox reaction promoters and alkali ions and/or protons.

Electrochromic Vanadium-pentoxide- based Films: Structural, Electrochemical and Optical Properties

Abstract: Crystalline VO2.5 films were prepared by reactive dc magnetron sputtering followed by annealing posttreatment. Lithium was inserted electrochemically from an electrolyte so that LixVO2.5 (0

A Dual‐Mode Molecular Switching Device: Bisphenolic Diarylethenes with Integrated Photochromic and Electrochromic Properties

Abstract: The bisphenolic dithienylethene molecules 1a and 1b were synthesized in overall yields of 45% from 4-bromoanisole and 44% from 2.6-di-tert-butyl-4-iodophenol, respectively. The corresponding extended quinones 3a and 3b were also prepared. Photochemical studies showed that compounds 1 are photochromic; the open forms 1 could be converted with UV light of 312nm to the closed coloured forms 2 with photostationary states lying at essentially complete conversion (> 98%). The 1a-2a system was found to exhibit good resistance to photofatigue and thermal stability for both photoisomers. Cyclic voltammetry studies involving the 2/3 couples showed that whereas 2b undergoes irreversible oxidation at + 0.85 V (vs. SCE in THF), the hydroquinone 2a is reversibly oxidized at an E1/2 of + 0.72V (in MeCN, quasi-reversibly in THF at + 0.81 V); this reflects the differences in deprotonation behaviour of the generated QH2/2+ species. The large difference in oxidation potential between 1a and 2a allows the photochemical switching of redox properties. In a complementary fashion, redox switching of the photochromic properties within the 2a-3a pair is possible since 3a is stable to visible light. Owing to this unique behaviour, the triad consisting of 1-3a represents a novel molecular device with mutually regulating photo- and electrochromic behaviour. In addition, the ability to interconvert between the three stable states makes the system well-suited as the basis for an optical memory system with multiple storage and nondestructive readout capacity through a write-lock-read-unlock-erase cycle.

Electrochromic mirror for vehicles

Abstract: A rearview mirror system for a vehicle having an electrochromic reflective element and heating means for uniformly heating substantially the entire reflectance surface in order to promote uniform coloration of the reflectance surface to a desired reflectance level. The reflective element is illustrated as an all solid-state electrochromic element having a large area reflectance surface for use as the exterior mirrors of a truck or other large vehicle. The application of energy to the heater can be controlled on the basis of a low ambient light condition and an ambient temperature that is low but not necessarily freezing, such as between 5° C. and 20° C. The heater can be resistance film that is evenly covering a surface of the reflective element and divided into first and second regions by an insulating break in the resistance film. Energy may be applied to one region in order to heat the reflectance element at a high rate to remove frost and dew. Energy may be applied to both regions in order to apply heat at a lower rate for even coloration of the mirror.

Electrochromic layer and devices comprising same

Abstract: The present invention provides improved electrochromic layers, which comprise polymeric matrices with electrochromic solutions interspersed therein. Varying an electrical potential difference across a layer of the invention results in reversible variation in the transmittance of light across the layer because of electrochemical processes in the electrochromic solution of the layer. The invention further provides electrochromic devices, in which the electrochromic layers of the invention provide reversibly variable transmittance to light, and various apparatus in which the devices of the invention provide light-filtering or light-color modulation. Such apparatus include windows, including those for use inside and on the outside walls of buildings and in sunroofs for automobiles, and variable reflectance mirrors, especially rearview mirrors for automobiles.

Precursor solutions for forming coatings

Abstract: An electrochromic coating is produced by adding an organic moiety to a solution of an electrochromic precursor, said organic moiety having a decomposition temperature greater than, or a vapor pressure sufficiently low at, the temperature at which solution solvent is removed, such that said organic moiety remains integral with the electrochromic precursor coating on said substrate after said solvent evaporates, and said organic moiety having a decomposition temperature lower than, or a vapor pressure sufficiently high at, the temperature at which said electrochromic precursor coating is converted to an electrochromic coating that said moiety is substantially removed from said coating before or during said conversion.

Inorganic Non-Oxide Electrochromic Materials

Abstract: There are many transition metal hexacyanometallates, and PB is only one–but the most well known and widely studied–member of a group of materials. This chapter focuses on the structure of PB and its capability for oxidation and reduction, the preparation and characterization of thin films, and the optical properties of films. It deals with inorganic non-oxide electrochromic materials. Inorganic non-oxide electrochromic materials are of great importance as— few of the materials, such as W sulfide and heteropolyacids (notably polytungstic acid), have an obvious kinship to electrochromic W oxide, new mechanisms for electrochromic modulation of the optical properties are conceivable among materials such as some metal nitrides, and there are materials that show electrochromism yet their main application may be as counterelectrodes in metal-oxide-based electrochromic devices; graphite, β-zirconium nitride chloride, and Prussian Blue (PB) belong to this category.

Handbook of Electromagnetic Materials: Monolithic and Composite Versions and Their Applications

Abstract: Introduction Dielectric Materials Electrical Insulating Materials Composite Dielectric Materials Complex Permittivity of Dielectric Composite Materials Composite Dielectric Materials with a Discrete Conducting Phase Conductor-Loaded Polymeric and Ceramic Materials Conducting Polymeric Materials Conductive Materials Semiconducting Materials Superconducting Materials Ferroelectric Materials Peizoelectric Composite Materials Ferromagnetic Materials Ferrite Materials Solid Electrolytic Materials Electrooptic Materials Electrochromic Materials Electronic Packing Materials Static Control Materials Electromagnetic Shielding Materials Electromagnetic Wave Absorbing Materials Electromagnetic Smart Materials Electrorheological Materials Electromagnetic Chiral Materials Electromagnetic Phantom Materials

Nickel Oxide Electrochromic Thin Films Prepared by Reactive DC Magnetron Sputtering

Abstract: Nickel oxide electrochromic thin films were prepared by reactive DC magnetron sputtering. The as-deposited optical property and electrochromic behavior strongly depended on the target operation mode and the substrate temperature. The sample sputtered with low oxygen flow rate, high power and substrate temperature of 200-300° C showed a wide transmittance modulation range, and the deposition rate was as high as 30 nm/min. Its integrated luminous transmittance could be controlled from 6.6 to 82.3%. X-ray diffraction measurements of this sample in a colored state and bleached state suggested that the boundary and surface of NiO microcrystallites played an important role in the electrochromic reaction of sputtered nickel oxide films.

Characterization and Stability of Electrochromic MoO3 Thin Films Prepared by Electrodeposition

Abstract: Electrochemical, spectroscopic, and structural measurements were used to characterize the electrochromic behavior and stability of electrodeposited MoO 3 thin films. These films are prepared from metal/hydrogen peroxide solution on transparent conductive glass (i.e., ITO). The as-deposited films are partially crystalline and show an improvement in crystallinity after heat-treatment in air at 260°C. These films display reversible electrochromic properties from blue to clear, when cycled in a 1 M solution of lithium perchlorate in propylene carbonate between -0.5 and +2.5 V. The observed effects of heat-treatment on the electrochromic properties are discussed and related to x-ray photoelectron spectroscopy analysis. The elemental depth profiles of colored MoO 3 films were analyzed by secondary ion mass spectrometry.

Electrochemical and structural studies on soluble and conducting polymer from o‐phenylenediamine

Abstract: A conducting polymer, poly(o-phenylenediamine) (PoPD), has been obtained as stable film onto an electrode surface by the electropolymerization of o-phenylenediamine in 0.1 mol dm -3 H 2 SO 4 . The film thickness did not exceed 0.85 μm because of its low electrical conductivity. The virgin doped polymer film was soluble in dimethylsulfoxide, N,N-dimethylformamide, acetone, and tetrahydrofuran without any pretreatment. The highest solubility obtained was 17 g dm -3 in dimethylsulfoxide. A cast film of PoPD on a substrate was prepared from its dimethylsulfoxide solution. The mean molecular weight of PoPD was found to be 11,000 with the gel permeation chromatography. The STM observation exhibited that the cast film was considerably uniform compared to the electrodeposited film. The cyclic voltammogram of such film showed a reversible redox property accompanied with excellent electrochromism between transparent yellow and brown. It was suggested from the 1 H-FTNMR and FTIR spectra and the elemental analysis that the polymeric backbone has 1,4-substituted benzenoid-quinoid structure. ® 1995 John Wiley & Sons, Inc.

Synthesis of a Novel Type of Electrochemically Doped Vinyl Polymer Containing Pendant Terthiophene and Its Electrical and Electrochromic Properties

Abstract: A novel kind of electrochemically doped poly(5-vinyl-2,2':5',2''-terthiophene) has been prepared by electrochemical doping of poly(5-vinyl-2,2':5',2''-terthiophene) and by electrolytic polymerization of 5-vinyl-2,2':5',2''-terthiophene in the presence of tetra-n-butylammonium perchlorate as a supporting electrolyte. The electrochemically doped poly(5-vinyl-2,2':5',2''-terthiophene), obtained as bluish purple lustrous films, is identified as a partially oxidized radical-cation salt with ClO 4 - as a dopant, having a partially cross-linked structure due to the coupling reaction of the radical cation of the pendant terthiophene moiety. The polymer with a degree of doping of 45% exhibits a room-temperature conductivity of 2×10 -8 S cm -1 with an activation energy of 0.5 eV. The polymer undergoes a reversible clear color change from bluish purple to pale yellowish orange and vice versa on electrochemical dedoping and doping and functions as a novel class of potential electrochromic material

Electrochromic edge isolation-interconnect system, process and device for its manufacture

Abstract: An electrochromic device for use in the field of optical lenses, such as eyewear or camera lenses. The device may also be used for windows, displays, mirrors or capacitors. The device comprises a substrate (12) having an expanse (18) and an edge region. A first electrode layer (28) is coated on the expanse and extends substantially across the expanse and into the edge region. An electrochromic layer (30) is coated on the first electrode so that the first electrode layer physically isolates the electrochromic layer from the substrate. A second electrode layer (32) is coated on the electrochromic layer, so that the electrochromic layer physically isolates the second electrode layer from the first electrode layer. A first contact (46) is electrically connected to the first electrode layer. An isolative barrier (50) is coated on the first electrode layer in the edge region. A second contact (48) is electrically connected to the second electrode layer. The isolative barrier electrically isolates the first contact from the second electrode layer and electrically isolates the second contact from the first electrode layer. In another embodiment, the invention comprises an edge-isolation channel formed in the edge region of the substrate. In another embodiment, the invention comprises a system including insulative material and a channel to achieve edge-wise electrical isolation and interconnection between the layers. The invention may also comprise a conductive elastomeric pad for electrically connecting a contact and a conductor. The invention also comprises a process for manufacturing an electrochromic device, the process including the steps of using a release agent. The invention also comprises a device and an associated process, for applying coating material to the perimeter of an eccentric substrate. The invention also comprises a process of mass producing large substrates with layers coated thereon such that the substrates can be stored, and thereafter cut to custom sizes. A channel is then cut in the custom-sized device to permit edge-wise electrical isolation and connection to power the device.

Angular selective transmittance through electrochromic tungsten oxide films made by oblique angle sputtering

Abstract: Tungsten oxide films were made by magnetron sputtering with a large angle between the substrate normal and the direction of the deposition flux. Scanning electron microscopy displayed a microstructure composed of inclined columns. Spectrophotometric measurements on films with different amounts of electrochemically intercalated Li+ ions showed pronounced angular selective transmittance together with electrochromism.

Bulk Crystalline Tungsten Oxide

Abstract: Publisher Summary This chapter on bulk crystalline W oxide provides a baseline for discussing the electrochromic films and also serves to introduce a number of important concepts. Tungsten oxide is by far the most extensively studied electrochromic material. Tungsten trioxide crystals have perovskite-like atomic configurations based on comer-sharing WO6 octahedra. Deviations from the ideal cubic perovskite-like structure correspond to antiferroelectric displacements of W atoms and to mutual rotations of oxygen octahedra. The magnitude of the distortion depends on the temperature, which is in agreement with the behavior of most perovskites, and pure WO3 single crystals go through structural transformations according to the sequence tetragonal→orthorhombic→monoclinic→triclinic→monoclinic as the temperature is lowered from 900 to -189°C. Tungsten oxide has a tendency to form substoichiometric phases containing edge-sharing octahedra.

Growth of Indium‐Tin‐Oxide Thin Films by Atomic Layer Epitaxy

Abstract: Transparent and conducting indium-tin-oxide (ITO) finds use in numerous thin-film applications, e.g., as transparent electrodes in flat panel displays and electrochromic windows, as active and passive components in photovoltaic devices, and as long infrared wavelength (IR) radiation reflecting heat mirror layers in energy efficient windows. Indium-tin-oxide thin films were deposited by atomic layer epitaxy at 500 C using InCl{sub 3}, SnCl{sub 4}, and water as precursors. The films were characterized by means of X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, polarography, and by optical and electrical measurements. The films had polycrystalline In{sub 2}O{sub 3} structure. In addition, the SnO{sub 2} phase was detected in films containing the highest tin contents. High transparencies and resistivities in the order of 2.4{times}10{sup {minus}4} {Omega}cm could be achieved by optimizing the tin doping procedure. Postannealing decreased the resistivity about 5%.