The Experts below are selected from a list of 2004 Experts worldwide ranked by ideXlab platform

Xungang Diao - One of the best experts on this subject based on the ideXlab platform.

  • enhanced Electrochromism in short wavelengths for nio li mg films in full inorganic device ito nio li mg ta2o5 wo3 ito
    Electrochimica Acta, 2018
    Co-Authors: Dongmei Dong, Wenwen Wang, Antoine Barnabe, Lionel Presmanes, Aline Rougier, Guobo Dong, Fan Zhang, Xungang Diao
    Abstract:

    Great interest has been drawn to the Electrochromism demonstrated by inorganic materials, leading to various applications including smart windows and displays. NiO, as a cheap material, shows anodic Electrochromism and is highly suitable for device applications in conjunction with WO3, but its strong optical absorbance has been largely overlooked. Herein, improved electrochromic properties in particular in short wavelengths was achieved by co-doping of Mg and Li in NiO:(Li, Mg) thin films grown using RF sputtering. Secondary Ion Mass Spectroscopy technique in combination with X-ray Photoelectron Spectroscopy characterization provides direct evidence of the introduction of Mg as well as Li in the film. Whatever the Li and Mg content, X-Ray Diffraction and Raman spectroscopy studies only bring out the NiO face-centered cubic rock salt structure. Electrochemical cycling shows pronounced anodic Electrochromism for NiO:(Li, Mg) thin films. Inorganic all-solid-state monolithic multilayered devices are traditionally composed of a pair of electrodes with NiO and WO3 separated by Li containing electrolyte such as LiTaO3 or LiNbO3 sputtered from expensive but low efficient ceramic targets. Based on optimal NiO:(Li, Mg) films, large switchable Electrochromism both in visible (∼58%) and ultraviolet band (∼50%) is reconciled in electrochromic device Glass/ITO/NiO:(Li, Mg)/Ta2O5/WO3/ITO. The co-doping of NiO with Mg and Li is capable of simultaneously widening the gap and avoiding the use of Li containing electrolyte, through NiO pre-lithiation. We believe the new, low-cost approach would provide references with respect to practical applications desired for their successful commercial mass production.

Yuwu Zhong - One of the best experts on this subject based on the ideXlab platform.

  • nanocrystalline sb doped sno2 films modified with cyclometalated ruthenium complexes for two step Electrochromism
    Dalton Transactions, 2019
    Co-Authors: Jiang-yang Shao, Yuwu Zhong
    Abstract:

    Sb-Doped nanocrystalline SnO2 (SnO2:Sb) thin films functionalized with cyclometalated ruthenium complexes 1 or 2 on FTO conductive glasses have been prepared and characterized. These complexes contain a redox-active amine unit separated from the ruthenium ion by a phenyl or biphenyl linker, respectively, to modify the absorption wavelengths at different redox states. Near-infrared Electrochromism of both films has been examined by oxidative spectroelectrochemical measurements and double-potential-step chronoamperometry. A contrast ratio (ΔT%) of 33% at 1070 nm and 63% at 696 nm has been achieved for the SnO2:Sb/1 film in two stepwise oxidation processes, respectively. The other film with complex 2 shows two-step Electrochromism at 1310 and 806 nm with ΔT% of 36% and 76%, respectively. The response time of electrochromic switching is around a few seconds. Taking advantage of the good contrast ratio, the rapid response, and the long retention time of each oxidation state, these films have been successfully used to demonstrate surface-confined flip-flop memory functions with a high ON/OFF ratio.

  • Electrochromism in Electropolymerized Films of Pyrene-Triphenylamine Derivatives
    MDPI AG, 2019
    Co-Authors: Jiang-yang Shao, Yuwu Zhong
    Abstract:

    Two star-shaped multi-triphenylamine derivatives 1 and 2 were prepared, where 2 has an additional phenyl unit between a pyrene core and surrounding triphenylamine units. The oxidative electropolymerization of 1 and 2 occurred smoothly to give thin films of polymers P1 and P2. The electrochemistry and spectroelectrochemistry of P1 and P2 were examined, showing two-step absorption spectral changes in the near-infrared region. The electrochromic properties, including contrast ratio, response time, and cyclic stability of P1 and P2 were investigated and compared. Thin film of P2 displays slightly better electrochromic performance than P1, with a contrast ratio of 45% at 1475 nm being achieved

  • near infrared and two wavelength Electrochromism based on nanocrystalline tio2 films functionalized with ruthenium amine conjugated complexes
    Inorganic Chemistry, 2017
    Co-Authors: Jiang-yang Shao, Yuwu Zhong
    Abstract:

    Two cyclometalated ruthenium complexes 2 and 4 containing a redox-active amine substituent and three carboxylic acid groups were synthesized, where the ruthenium ion and the amine site were separated by a phenyl or biphenyl bridge for 2 and 4, respectively. Nanocrystalline TiO2 films on fluorine doped SnO2 (FTO)/glass substrates anchored with 2 or 4 were prepared. These films display two consecutive anodic waves in the potential region between +0.1 and +1.0 V vs Ag/AgCl. Among four organic solvents examined, the FTO/TiO2/2 film displays the best cyclic electrochemical stability in ClCH2CH2Cl. Both films exhibit promising two-step Electrochromism in the near infrared region. A contrast ratio (ΔT%) of 42% at 1000 nm and 40% at 680 nm was achieved for the FTO/TiO2/2 film in the single- and double-oxidation process, respectively. In contrast, the FTO/TiO2/4 film shows Electrochromism at 1300 nm (ΔT% = 58%) and 780 nm (ΔT% = 59%) in the single- and double-oxidation process, respectively. The coloration efficiency of these processes varies in a range of 150-270 cm2/C. These films are potentially useful as variable optical attenuators for telecommunications.

  • electropolymerized films of redox active ruthenium complexes for multistate near infrared Electrochromism ion sensing and information storage
    ChemInform, 2016
    Co-Authors: Jiang-yang Shao, Changjiang Yao, Binbin Cui, Zhongliang Gong, Yuwu Zhong
    Abstract:

    Abstract This paper summarizes our recent progress on the preparations and applications of electropolymerized thin films of redox-active ruthenium complexes. Thin films of vinyl-functionalized diruthenium or ruthenium-amine conjugated complexes are prepared by reductive electropolymerization. The resulting films are useful for multistate near-infrared Electrochromism, ion sensing, and mimicking flip-flop and flip-flap-flop logic gates. The oxidative electropolymerization of diruthenium complexes with two distal triarylamine units affords electropolymers with an alternating diruthenium and tetraphenylbenzidine structural unit. The applications of the resulting films in multistate near-infrared Electrochromism and resistive memory are discussed.

  • ruthenium amine conjugated organometallic materials for multistate near ir Electrochromism and information storage
    ChemInform, 2016
    Co-Authors: Jianhong Tang, Binbin Cui, Changjiang Yao, Yuwu Zhong
    Abstract:

    Monometallic and dimetallic complexes with the ruthenium-amine conjugated structural unit have been prepared. These complexes display consecutive redox waves with low potentials and rich and intense absorptions in the near-infrared region. The electrochemical and spectroscopic properties can be modulated using substituents or auxiliary ligands with different electronic natures. Through simple functionalization, electropolymerized or monolayer thin films of these complexes have been prepared. These films display multistate near-infrared Electrochromism with good contrast ratios and long optical retention times. In addition, flip-flop and flip-flap-flop memories have been demonstrated on the basis of these thin films.

Hui Huang - One of the best experts on this subject based on the ideXlab platform.

  • multicolor and fast Electrochromism of nanoporous nio poly 3 4 ethylenedioxythiophene composite thin film
    Electrochemistry Communications, 2009
    Co-Authors: Xinhui Xia, Jun Zhang, X H Huang, X L Wang, Wenkui Zhang, Hui Huang
    Abstract:

    Abstract We report a nanoporous NiO/poly(3,4-ethylenedioxythiophene) (PEDOT) composite film using a highly porous NiO film as a template by the combination of chemical bath deposition and electro-polymerization methods. The as-prepared NiO/PEDOT composite film has an interconnecting reticular morphology with nanometer sized pores ranging from 20–150 nm. The NiO/PEDOT composite film exhibits multicolor Electrochromism with reversible color changes from purple to light blue brown and presents a transmittance variation of 31% at 600 nm. Fast switching speed is achieved in this composite film, and the response time for oxidation and reduction is 500 and 600 ms, respectively.

  • Enhanced electrochromics of nanoporous cobalt oxide thin film prepared by a facile chemical bath deposition
    Electrochemistry Communications, 2008
    Co-Authors: J.p. Tu, Xiuli Wang, X H Huang, Wenkui Zhang, Jinsuo Zhang, Hui Huang
    Abstract:

    A highly porous cobalt oxide thin film was prepared on ITO glass by a facile chemical bath deposition (CBD) method. The as-prepared cobalt oxide film has an intercrossing net-like morphology. The electrochromic performance of cobalt oxide film was investigated in 0.1 M KOH by means of transmittance, cyclic voltammetry (CV) and chronoamperometry (CA) measurements. The cobalt oxide thin film exhibits a noticeable Electrochromism with reversible color changes from pale yellow to dark grey and presents a transmittance variation with 36% in the visible range. The porous cobalt oxide thin film also shows good reaction kinetics with fast switching speed, and the coloration and bleaching time are 2.5 and 2 s, respectively.

Dongmei Dong - One of the best experts on this subject based on the ideXlab platform.

  • enhanced Electrochromism in short wavelengths for nio li mg films in full inorganic device ito nio li mg ta2o5 wo3 ito
    Electrochimica Acta, 2018
    Co-Authors: Dongmei Dong, Wenwen Wang, Antoine Barnabe, Lionel Presmanes, Aline Rougier, Guobo Dong, Fan Zhang, Xungang Diao
    Abstract:

    Great interest has been drawn to the Electrochromism demonstrated by inorganic materials, leading to various applications including smart windows and displays. NiO, as a cheap material, shows anodic Electrochromism and is highly suitable for device applications in conjunction with WO3, but its strong optical absorbance has been largely overlooked. Herein, improved electrochromic properties in particular in short wavelengths was achieved by co-doping of Mg and Li in NiO:(Li, Mg) thin films grown using RF sputtering. Secondary Ion Mass Spectroscopy technique in combination with X-ray Photoelectron Spectroscopy characterization provides direct evidence of the introduction of Mg as well as Li in the film. Whatever the Li and Mg content, X-Ray Diffraction and Raman spectroscopy studies only bring out the NiO face-centered cubic rock salt structure. Electrochemical cycling shows pronounced anodic Electrochromism for NiO:(Li, Mg) thin films. Inorganic all-solid-state monolithic multilayered devices are traditionally composed of a pair of electrodes with NiO and WO3 separated by Li containing electrolyte such as LiTaO3 or LiNbO3 sputtered from expensive but low efficient ceramic targets. Based on optimal NiO:(Li, Mg) films, large switchable Electrochromism both in visible (∼58%) and ultraviolet band (∼50%) is reconciled in electrochromic device Glass/ITO/NiO:(Li, Mg)/Ta2O5/WO3/ITO. The co-doping of NiO with Mg and Li is capable of simultaneously widening the gap and avoiding the use of Li containing electrolyte, through NiO pre-lithiation. We believe the new, low-cost approach would provide references with respect to practical applications desired for their successful commercial mass production.

Eunkyoung Kim - One of the best experts on this subject based on the ideXlab platform.

  • Programmable dual Electrochromism in azine linked conjugated polymer
    'The Optical Society', 2018
    Co-Authors: Minsu Han, Yuna Kim, Mithrabinda K. Poduval, Haijin Shin, Nobuyuki Tamaoki, Park Taiho, Eunkyoung Kim
    Abstract:

    A conjugated polymer consisting of tri-EDOT and azine groups was synthesized and explored for a programmable dual electrochromic device. Electrochemical doping (oxidation) and de-doping (reduction) resulted in the two distinct redox pairs, depending on the applied potential range. In situ spectroelectrochemical analyses revealed that the stepwise redox process of two units was associated with dual electrochromic responses: tri-EDOT unit for purple Electrochromism followed by azine unit for blue Electrochromism. Dual Electrochromism of purple and blue was attainable at below 1.0 V which could induce the color transition upon the potential application of around ± 1 V. Maximum coloration efficiency of 393 cm2/C with a response time of 1 s was obtained.1121sciescopu

  • Programmable dual Electrochromism in azine linked conjugated polymer
    'The Optical Society', 2018
    Co-Authors: Minsu Han, Yuna Kim, Mithrabinda K. Poduval, Haijin Shin, Nobuyuki Tamaoki, Park Taiho, Eunkyoung Kim
    Abstract:

    A conjugated polymer consisting of tri-EDOT and azine groups was synthesized and explored for a programmable dual electrochromic device. Electrochemical doping (oxidation) and de-doping (reduction) resulted in the two distinct redox pairs, depending on the applied potential range. In situ spectroelectrochemical analyses revealed that the stepwise redox process of two units was associated with dual electrochromic responses: tri-EDOT unit for purple Electrochromism followed by azine unit for blue Electrochromism. Dual Electrochromism of purple and blue was attainable at below 1.0 V which could induce the color transition upon the potential application of around ± 1 V. Maximum coloration efficiency of 393 cm2/C with a response time of 1 s was obtained.12

  • color combination of conductive polymers for black Electrochromism
    ACS Applied Materials & Interfaces, 2012
    Co-Authors: Haijin Shin, Yuna Kim, T Bhuvana, Jiyea Lee, Xu Yang, Cheolmin Park, Eunkyoung Kim
    Abstract:

    Conducting polymers that absorb three primary colors, red, green, and blue (RGB), were introduced with a yellow electrochromic polymer (Y) for the preparation of black electrochromic devices. Red poly(3-hexylthiophene) (P3HT) and blue poly(3,4-ethylenedioxythiophene) (PEDOT) were coated on one side of the electrode as a cathodically coloring electrochromic (EC) layer, while green poly(aniline-N-butylsulfonate) (PANBS) and yellow EC poly{[1,3-bis(9′,9′-dihexylfluoren-20-yl)azulenyl]-alt-[2″,7″-(9″,9″-dihexylfluorenyl]} (PDHFA) were coated on the opposite electrode to complete a complementary EC device. The yellow PDHFA layer effectively compensated for absorption below 450 nm and above the 600 nm region, which was lacking in the RGB electrode. The resultant RGBY ECD provided a black color near the CIE black with L*, a*, and b* values of 32, −1.1, and 3.7, respectively, covering a broad absorption in the visible range in the colored state. The state of the black EC device was maintained, even after the elec...

  • visible to near ir Electrochromism and photothermal effect of poly 3 4 propylenedioxyselenophene s
    Macromolecules, 2011
    Co-Authors: Byeonggwan Kim, Jeonghun Kim, Eunkyoung Kim
    Abstract:

    A new selenophene derivative, 3,4-propylenedioxyselenophene (ProDOS), was electropolymerized to a polymeric thin film which demonstrated wide spectral tunability from the visible to near-infrared (NIR) region. The anodic and cathodic peaks of the polymeric ProDOS (PProDOS) were observed at +0.22 and −0.30 V, showing a narrow band gap. In the visible region, the PProDOS film showed color change from navy blue in its dedoped state (−0.12 V vs Ag/AgCl) to highly transparent pale gray green in its doped state (0.68 V vs Ag/AgCl) with a high coloration efficiency (CE) of 273 cm2 C–1 and large transmittance change (contrast ratio of 5.7). The color change of the PProDOS film by Electrochromism in the visible region was simultaneously accompanied by NIR Electrochromism. Upon exposure to a NIR source (0.7 W cm–2), the doped PProDOS film resulted in a temperature rise of 10.7 °C compared to that of the bare indium tin oxide (ITO) coated glass, while the navy blue colored PProDOS film experienced a temperature rise...

  • tetrazine based electrofluorochromic windows modulation of the fluorescence through applied potential
    Journal of Electroanalytical Chemistry, 2009
    Co-Authors: Yuna Kim, Gilles Clavier, Eunkyoung Kim, Laurent Galmiche, Pierre Audebert
    Abstract:

    A series of new electrofluorescent switches was prepared using electroactive fluorescent tetrazines, an original family of molecules featuring both highly stable reduced anion-radicals and fluorescence in the neutral state. The cells were prepared with four layers: the tetrazine polymer film, a photo cured polymer electrolyte film, and two indium-tin oxide films as the two contact electrodes. When externally biased, the fluorescence of the tetrazine fluorophore can be switched on and off reversibly, according to its redox state through scanning the potential between two transparent ITO electrodes. Electrochromism of a tetrazine containing conducting polymer has also been examined.