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Showing papers on "Electrochromism published in 2003"


Journal ArticleDOI
TL;DR: The most important examples from major classes of electrochromic materials namely transition metal oxides, Prussian blue, phthalocyanines, viologens, fullerenes, dyes and conducting polymers (including gels) are described in this article.

743 citations


Journal ArticleDOI
TL;DR: Mesoporous WO3 films with a lamellar structure have been synthesized by electrodeposition using sodium dodecyl sulfate (SDS) as a templating agent as mentioned in this paper.
Abstract: Mesoporous WO3 films with a lamellar structure (see Figure) have been synthesized by electrodeposition using sodium dodecyl sulfate (SDS) as a templating agent. Compared to non-porous WO3 prepared with isopropanol instead of SDS, lamellar phase mesoporous WO3 showed higher photocatalytic activity and greater current density for hydrogen intercalation, probably due to the larger surface area of mesoporous WO3 and more facile charge transport.

449 citations



Patent
18 Mar 2003
TL;DR: In this paper, the authors proposed a method for sealing electrochromic displays from the outside environment and preventing ingress of contaminants into such a display, as well as adjusting the driving of electro-optic displays to allow for environmental and operating parameters.
Abstract: The invention relates to electro-optic displays and methods for driving such displays. The invention provides (i) electrochromic displays with solid charge transport layers; (ii) apparatus and methods for improving the contrast and reducing the cost of electrochromic displays; (iii) apparatus and methods for sealing electrochromic displays from the outside environment and preventing ingress of contaminants into such a display; and (iv) methods for adjusting the driving of electro-optic displays to allow for environmental and operating parameters.

355 citations


Journal ArticleDOI
TL;DR: In this paper, a large number of electrochromic devices for modulating transmittance and emittance are reviewed, both with and without self-powering by integrated solar cells.

321 citations


Journal ArticleDOI
TL;DR: In this paper, a very high contrast electrochromic composite was developed from the LBL assembly of two readily available cathodically coloring polymers: poly(hexyl viologen) (PXV) and the poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (SPS) colloid.
Abstract: Layer-by-layer (LBL) assembly is the ideal processing technique to combine two electrochromic polymers into a single thin film composite with fine control over morphology and composition. Here we present a very-high-contrast electrochromic composite developed from the LBL assembly of two readily available cathodically coloring electrochromic polymers: poly(hexyl viologen) (PXV) and the poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:SPS) colloid. Characterization of assembly reveals that film thickness increases exponentially with increasing layer-pair number, seemingly due to the globular nature of the PEDOT:SPS colloid. Elemental analysis confirmed the presence of both polymers in the final film and allowed the determination of a bulk composition profile. In detailed electrochemical and spectral investigations, the “dual electrochrome” was compared to single-electrochrome LBL films, confirming that both polymers contribute to electrochromic switching. Due to the unusual film architectur...

268 citations


Journal ArticleDOI
TL;DR: In this article, the authors discuss three aspects of electrochromic smart windows, including their energy efficiency, durability and manufacturability, and present data on precharging of electro chromic nickel oxide films by ozone treatment.
Abstract: This paper covers three aspects of electrochromic smart windows. Their energy efficiency is discussed, and it is argued that a control strategy considering whether a room is in use or not can lead to large savings of the energy needed for space cooling. With regard to durability, it is shown that chemical compatibility between the electrolyte and electrochromic films of tungsten oxide and nickel oxide can be achieved without loss of optical transparency. Finally, we consider device manufacturability and present data on precharging of electrochromic nickel oxide films by ozone treatment.

264 citations


Journal ArticleDOI
TL;DR: Both photochromic and unprecedented electrochromic properties have been observed for a class of 1,2-bis(3-thienyl)cyclopentene derivatives bearing either a thiophene or a phenyl group attached to the reactive carbon centers.
Abstract: Both photochromic and unprecedented electrochromic properties have been observed for a class of 1,2-bis(3-thienyl)cyclopentene derivatives bearing either a thiophene or a phenyl group attached to the reactive carbon centers. These compounds can be interconverted between their colorless ring-open and colored ring-closed states using UV and visible light, respectively. They can also be catalytically transformed from their ring-closed states to their ring-open states through electrochemical or chemical oxidation.

213 citations


Patent
11 Sep 2003
TL;DR: In this paper, an electrochromic device with a transmittance that varies in response to an electrical signal, a base substrate disposed in spaced relation to the electro-chromic element, a seal disposed between the base substrate and the element, and an optical sensor is disposed.
Abstract: The device of the present invention includes an electrochromic element having a transmittance that varies in response to an electrical signal, a base substrate disposed in spaced relation to the electrochromic element, a seal disposed between the base substrate and the electrochromic element, and an optical sensor. The seal, base substrate, and electrochromic element form a sealed cavity therebetween, in which the optical sensor is disposed. According to another embodiment, an electrochromic device is provided that includes a first substrate, an electrochromic medium disposed on the first substrate, a pair of electrodes in contact with the electrochromic medium, a pair of conductive clips, each in electrical contact with a respective one of the electrodes, and two pairs of electrical lead posts for mounting the first substrate to the circuit board. Each pair of lead posts is attached to, and extends from, a respective one of the conductive clips. According to another embodiment, an imaging device is disclosed having an image recorder for recording a scene or object, and an electrochromic element positioned between the image recorder and the object or scene to be imaged. The electrochromic element is configured to exhibit a non-uniform transmittance in response to an applied electrical signal.

187 citations


Journal ArticleDOI
TL;DR: A combination of cyclic voltammetry, UV-vis-NIR spectroelectrochemistry, time-dependent density functional theory (TD-DFT), and Z-scan measurements employing a modified optically transparent thin-layer electrochemical cell has been used to identify and assign intense transitions of metal alkynyl complexes at technologically important wavelengths in the oxidized state and to demonstrate a facile electrochromic switching of optical nonlinearity.
Abstract: A combination of cyclic voltammetry, UV−vis−NIR spectroelectrochemistry, time-dependent density functional theory (TD-DFT), and Z-scan measurements employing a modified optically transparent thin-layer electrochemical (OTTLE) cell has been used to identify and assign intense transitions of metal alkynyl complexes at technologically important wavelengths in the oxidized state and to utilize these transitions to demonstrate a facile electrochromic switching of optical nonlinearity. Cyclic voltammetric data for the ruthenium(II) complexes trans-[RuXY(dppe)2] [dppe = 1,2-bis(diphenylphosphino)ethane, X = Cl, Y = Cl (1), C⋮CPh (2), 4-C⋮CC6H4C⋮CPh (3); X = C⋮CPh, Y = C⋮CPh (4), 4-C⋮CC6H4C⋮CPh (5)] show a quasi-reversible oxidation at 0.50−0.60 V (with respect to ferrocene/ferrocenium 0.56 V), which is assigned to the RuII/III couple. The ruthenium(III) complex cations trans-[RuXY(dppe)2]+ were obtained by the in situ oxidation of complexes 1−5 using an OTTLE cell. The UV−vis−NIR optical spectra of 1+−5+ contain...

185 citations


Journal ArticleDOI
TL;DR: In this paper, a comparative study of the optical and electrochromic properties of different types of WO 3 thin films has been carried out by atomic force microscopy (AFM), optical studies and ATR-FTIR spectroscopy.

Patent
29 Sep 2003
TL;DR: In this article, an electrical conductor is provided to electrically couple a portion of a first conductive layer provided on the rear surface of the front element with a part of a second conductive surface on the front of the rear element.
Abstract: To allow an electrochromic device to have little or no offset between its front and rear elements, an electrical conductor may be provided to electrically couple a portion of a first conductive layer provided on the rear surface of the front element with a portion of a second conductive layer provided on the front surface of the rear element. The electrical conductor may be in the form of a conductive portion of the seal. To prevent shorting across the electrochromic medium, at least one of the first and second conductive layers is separated into a first portion and a second portion that is electrically isolated from the first portion and is in electrical contact with the electrochromic material. An elastomeric bezel may be utilized. Also, an edge seal may optionally be employed so as to reduce the need or width of the bezel.

Journal ArticleDOI
TL;DR: Reflective and absorptive/transmissive polymer electrochromic devices (ECDs) composed of spray-coated films of poly(3,3-bis(octadecyloxymethyl)-3,4-dihydro-2H-thieno[3, 4-b][1, 4]dioxepine) are constructed and evaluated in this article.
Abstract: Reflective and absorptive/transmissive polymer electrochromic devices (ECDs) composed of spray-coated films of poly(3,3-bis(octadecyloxymethyl)-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine) (PProDOT(CH2OC18H37)2) and poly(3,3-bis(2-ethylhexyloxymethyl)-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine) (PProDOT(CH2OEtHx)2) layers as cathodically coloring polymers and poly(3,6-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-9-methyl-9H-carbazole) (PBEDOT-NMeCz) as the anodically coloring polymer have been constructed and evaluated. These devices exhibit low switching voltages (±1.2 V), high visible contrast values, sub-second switching times, and high switching stability in atmospheric conditions. The reflective ECD comprising PProDOT(CH2OEtHx)2 as the active layer demonstrates an unusual electrochromic behavior. By regulating the applied voltage, a high reflectance contrast of greater than 70% ΔT was achieved in the NIR region (2 µm) without any noticeable color change of the device.

Journal ArticleDOI
TL;DR: A series of electrochromic N-substituted poly(3,4-propylenedioxypyrrole)s (PProDOPs) are reported in this paper, which exhibit the combined properties of a high (>3 eV) electronic band gap, colored oxidatively doped forms, and easily accessible, low redox potentials.
Abstract: A series of electrochromic N-substituted poly(3,4-propylenedioxypyrrole)s (PProDOPs) are reported, which exhibit the combined properties of a high (>3 eV) electronic band gap, colored oxidatively doped forms, and easily accessible, low redox potentials. Utilizing methyl (Me), propyl (Pr), octyl (Oct), propanesulfonated (PrS), and ethoxyethoxyethanol (Gly) pendants, the absorbance of the π−π* transition of the resulting polymers is blue-shifted when compared to the nonderivatized parent. For example, in the case of poly(N-ethoxyethoxyethanol ProDOP) (N-Gly PProDOP), this transition displays a maximum at 306 nm (onset at 365 nm), providing a colorless and highly transparent neutral polymer with a luminous transmittance greater than 99% for a film thickness of about 200 nm. N-Substituted PProDOPs display very well-defined cyclic voltammograms, with E1/2 < −0.1 V vs Fc/Fc+ (+0.2 V vs SCE), negative of the oxidation of water, as desired for materials having stable doped forms and long-lived redox switching pro...

Patent
06 May 2003
TL;DR: A display comprises spaced first and second electrodes, and a plurality of electrochromic nanoparticles disposed between the electrodes, each of the nanoparticles having an electron-rich state and an electron depleted state, the two states differing in at least one optical characteristic.
Abstract: A display comprises spaced first and second electrodes, and a plurality of electrochromic nanoparticles disposed between the electrodes, each of the nanoparticles having an electron-rich state and an electron-depleted state, the two states differing in at least one optical characteristic. Upon injection of charge from one of the electrodes, the nanoparticles switch between their electron-rich and electron-depleted states, thus changing an optical characteristic of the display.

Journal ArticleDOI
TL;DR: In this paper, a review of recent advancements of transparent oxide semiconductors (TOS) toward new frontiers of oxide electronics are reviewed based on their efforts, categorized as novel functional materials, heteroepitaxial growth techniques, and device fabrications.
Abstract: Recent advancements of transparent oxide semiconductors (TOS) toward new frontiers of “oxide electronics” are reviewed based on our efforts, categorized as “novel functional materials”, “heteroepitaxial growth techniques”, and “device fabrications”. Topics focused in this paper are: (1) highly conductive ITO thin film with atomically flat surface, (2) p-type TOS material ZnRh2O4, (3) deep-ultraviolet (DUV) transparent conductive oxide β-Ga2O3 thin film, (4) electrochromic oxyfuolide NbO2F, (5) single-crystalline films of InGaO3(ZnO)m grown by reactive solid-phase epitaxy, (6) p-type semiconductor LaCuOS/Se epitaxial films capable of emitting UV- and purple-light, (7) p–n homojunction based on bipolar CuInO2, (8) transparent FET based on single-crystalline InGaO3(ZnO)5 films, and (9) UV-light emitting diode based on p–n heterojunction.

Journal ArticleDOI
TL;DR: In this paper, the properties of three layer-by-layer (LBL) polymer electrolyte systems assembled from cationic layers of linear poly(ethylene imine) (LPEI), with anionic layers of Nafion, poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS), and poly(acrylic acid)(PAA).
Abstract: The layer-by-layer (LBL) deposition technique has been applied to the design of polymer electrolyte films appropriate for electrochemical applications such as sensors and electrochromic cells. In this work, we describe the properties of three LBL polymer electrolyte systems assembled from cationic layers of linear poly(ethylene imine) (LPEI), with anionic layers of Nafion, poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS), and poly(acrylic acid) (PAA). The assembly behavior of these systems was carefully examined, and ionic conductivity was determined using impedance spectroscopy. The influences of assembly conditions and water plasticization on ion conduction were elaborated. Room-temperature ionic conductivity greater than 10-5 S/cm can be achieved within LPEI/PAMPS and LPEI/PAA films, which is 2 orders of magnitude greater than the highest values previously described in LBL films. By manipulating a unique assembly mechanism, high ionic conductivity can be achieved in LPEI/PAMPS films at low pl...

Journal ArticleDOI
TL;DR: In this paper, thin films of tungsten oxide, molybdenum oxide and mixed MoO3-WO3 oxides were obtained by atmospheric pressure chemical vapor deposition (CVD).


Journal ArticleDOI
E. Washizu1, A. Yamamoto1, Y. Abe1, Midori Kawamura1, K. Sasaki1 
TL;DR: In this paper, the effects of deposition conditions, including substrate temperature and sputtering gas pressure, on the optical and electrochromic properties of WO3 films prepared by RF reactive sputtering were investigated.

Journal ArticleDOI
TL;DR: In this article, the transmittance of the TiO 2 anatase thin films was found to be strongly dependent on the Li + inserted charge, and it was shown that the fully colorated state of the anatase films is Li 0.5 with a crystalline structure of Imma space group symmetry.

Journal ArticleDOI
27 Mar 2003-Langmuir
TL;DR: Molybdenum trioxide (MoO3) thin films prepared by cathodic electrodeposition on indium−tin-oxide coated glass substrates from aqueous peroxo-polymolybdate solutions have been studied as a function.
Abstract: Molybdenum trioxide (MoO3) thin films prepared by cathodic electrodeposition on indium−tin-oxide coated glass substrates from aqueous peroxo-polymolybdate solutions have been studied as a function ...

Journal ArticleDOI
TL;DR: In this article, a voltammetric response was recorded for the reduction of the nanocrystals with quantitative injection of electrons in the 1Se state, and injection in 1Pe manifold was also achieved as evidenced by spectroscopic measurements.
Abstract: CdSe nanocrystal thin films exhibit stable and quantitative electrochemical responses when treated with cross-linking molecules such as dithiols or diamines. For the first time, a voltammetric response is recorded for the reduction of the nanocrystals with quantitative injection of electrons in the 1Se state. Injection in the 1Pe manifold is also achieved as evidenced by spectroscopic measurements. For a 100 nm thick film of 6.2 nm diameter nanocrystals, electrochromic changes are on 100 ms time scales, and remain robust after 10 000 cycles.

Journal ArticleDOI
TL;DR: In this article, a colorimetric study of these films showed distinctive color changes between red and blue as they were switched between reduced and oxidized states, which allowed the use of commercially available high oxidation potential thiophene monomers to provide electrochromic polymers.
Abstract: Electrochemical polymerization in the strong Lewis acid, boron trifluoride ethylether (BFEE), has been used to prepare electrochromic polythiophene (PTh) and its derivatives: poly(3-methylthiophene) (PMeTh), poly(3-bromothiophene) (PBrTh), and poly(3,4-dibromothiophene) (PDBrTh) The polymerization processes and properties of the resultant films are compared, where possible, to those carried out in traditional organic electrochemical solvents The polymerization of these high oxidation potential thiophene monomers in BFEE yielded good-quality, homogenous, and smooth electroactive and electrochromic films that could be repeatedly switched in common electrochemical solvents up to 240, 1380, 560, and 420 cycles for PTh, PMeTh, PBrTh, and PDBrTh, respectively, for 50 % retention of electroactivity A colorimetric study of these films showed distinctive color changes between red and blue as they were switched between reduced and oxidized states These findings allow the use of commercially available high oxidation potential thiophene monomers to provide electrochromic polymers, avoiding the use of other custom-synthesized monomers

Journal ArticleDOI
TL;DR: In this paper, a detailed systematic study of the tungsten oxide thin films has been carried out using WO 3 films after they were annealed at progressively increasing temperatures ranging from 350°C to 450°C in oxygen environments.

Journal ArticleDOI
TL;DR: In this paper, the authors report the progress that has been made in increasing the colour range and assessing the lifetime of electrochromic displays based on modified mesoporous electrodes, and they report that the performance of these displays is comparable to paper-based displays in readability, switching speed, power consumption and stability.

Journal ArticleDOI
TL;DR: In this paper, a stable electrochromic polymer, poly(1,4-bis(2-(3′,4′-ethylenedioxy)thienyl)-2-methoxy-5-2″-ethylhexyloxybenzene) (P(BEDOT-MEHB)) was synthesized and its electrochemical properties are reported.
Abstract: A highly stable new electrochromic polymer, poly(1,4-bis(2-(3′,4′-ethylenedioxy)thienyl)-2-methoxy-5-2″-ethylhexyloxybenzene) (P(BEDOT-MEHB)) was synthesized and its electrochemical and electrochromic properties are reported. P(BEDOT-MEHB) showed a very well defined electrochemistry with a relatively low oxidation potential of the monomer at + 0.44 V versus Ag/Ag+, E1/2 at – 0.35 V versus Ag/Ag+ and stability to long-term switching up to 5000 cycles. A high level of stability to over-oxidation has also been observed as this material shows limited degradation of its electroactivity at potentials 1.4 V above its half-wave potential. Spectroelectrochemistry showed that the absorbance of the π–π* transition in the neutral state is blue-shifted compared to PEDOT, displaying a maximum at 538 nm (onset at 640 nm), thus giving an almost colorless, highly transparent oxidized polymer with a bandgap of 1.95 eV. Different colors observed at different oxidation levels and strong absorption in the near-IR make this polymer a good candidate for several applications.

Journal ArticleDOI
TL;DR: The diphenylamino group is an effective handle for electropolymerization to give electron donor-acceptor conjugated polymers and interesting electrochromic and photoresponsive behavior of 13 has been investigated.

Journal ArticleDOI
TL;DR: In this article, the spectral variations of the optical transmission under polarization or illumination are reported for thin films of doped and undoped tungsten trioxide prepared by the sol-gel process.

Journal ArticleDOI
TL;DR: An unprecedented combination of photochromism and electrochromism is observed for two 1,2-bis(dithienyl)cyclopentene derivatives; the ring-opening reactions are photochemically driven while theRing-closing reactions can be triggered by electrochemical oxidation.