• Title/Summary/Keyword: electrochromic

Search Result 153, Processing Time 0.057 seconds

The Fabrication of Porous Nickel Oxide Thin Film using Anodization Process for an Electrochromic Device

  • Lee, Won-Chang;Choe, Eun-Chang;Hong, Byeong-Yu
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2016.02a
    • /
    • pp.407.1-407.1
    • /
    • 2016

  • Electrochromism is defined as a phenomenon which involves persistently repeated change of optical properties between bleached state and colored state by simultaneous injection of electrons and ions, sufficient to induce an electrochemical redox process. Due to this feature, considerable progress has been made in the synthesis of electrochromic (EC) materials, improvements of EC properties in EC devices such as light shutter, smart window and variable reflectance mirrors etc. Among the variable EC materials, solid-state inorganics in particular, metal oxide semiconducting materials such as nickel oxide (NiO) have been investigated extensively. The NiO that is an anodic EC material is of special interest because of high color contrast ratio, large dynamic range and low material cost. The high performance EC devices should present the use of standard industrial production techniques to produce films with high coloration efficiency, rapid switching speed and robust reversibility. Generally, the color contrast and the optical switching speed increase drastically if high surface area is used. The structure of porous thin film provides a specific surface area and can facilitate a very short response time of the reaction between the surface and ions. The large variety of methods has been used to prepare the porous NiO thin films such as sol-gel process, chemical bath deposition and sputtering. Few studies have been reported on NiO thin films made by using sol-gel method. However, compared with dry process, wet processes that have the questions of the durability and the vestige of bleached state color limit the thin films practical use, especially when prepared by sol-gel method. In this study, we synthesis the porous NiO thin films on the fluorine doped tin oxide (FTO) glass by using sputtering and anodizing method. Also we compared electrical and optical properties of NiO thin films prepared by sol gel. The porous structure is promised to be helpful to the properties enhancement of the EC devices.

  • PDF

Electrochromic Properties of Li+-Modified Prussian Blue (리튬이온이 첨가된 프루시안 블루의 전기변색 특성 연구)

  • Yoo, Sung-Jong;Lim, Ju-Wan;Park, Sun-Ha;Won, Ho-Youn;Sung, Yung-Eun
    • Journal of the Korean Electrochemical Society
    • /
    • v.10 no.2
    • /
    • pp.126-131
    • /
    • 2007

  • The durability problem of Prussian blue in non-aqueous $Li_+$-based electrolytes has been due to the degradation of the Prussian blue electrode matrix during the insertion/extraction processes by $Li_+$. In this work, we designed and synthesised the Prussian blue without reducing the electrochromic performance in non-aqueous $Li_+$-based electrolytes. Prussian blue was electrodeposited on a glass which has ITO coating, and the coating solution is a mixture solution of $FeCl_3\;and\;K_3Fe(CN)_6$ with deionized water added HCl, KCl, and LiCl, respectively. The durability of Prussian blue was evaluated by an in-situ transmittance measurement during a continuous and pulse potential cycling test, and measured by electroactive layer thickness due to evaluating the degradation.

  • https://doi.org/10.5229/JKES.2007.10.2.126 인용 PDF KSCI

Crystallinity Control Effects on Vanadium Oxide Films for Enhanced Electrochromic Performances (전기변색 성능 향상을 위한 바나듐산화물 막의 결정성 제어 효과)

  • Kim, Kue-Ho;Bae, Ju-Won;Lee, Tae-Kuen;Ahn, Hyo-Jin
    • Korean Journal of Materials Research
    • /
    • v.29 no.6
    • /
    • pp.385-391
    • /
    • 2019

  • In the present study, vanadium oxide($V_2O_5$) films for electrochromic(EC) application are fabricated using sol-gel spin coating method. In order to optimize the EC performance of the $V_2O_5$ films, we adjust the amounts of polyvinylpyrrolidone(PVP) added to the solution at 0, 5, 10, and 15 wt%. Due to the effect of added PVP on the $V_2O_5$ films, the obtained films show increases of film thickness and crystallinity. Compared to other samples, optimum weight percent(10 wt%) of PVP led to superior EC performance with transmittance modulation(45.43 %), responding speeds(6.0 s at colored state and 6.2 s at bleached state), and coloration efficiency($29.8cm^2/C$). This performance improvement can be mainly attributed to the enhanced electrical conductivity and electrochemical activity due to the increased crystallinity and thickness of the $V_2O_5$ films. Therefore, $V_2O_5$ films fabricated with optimized amount of PVP can be a promising EC material for high-performance EC devices.

  • https://doi.org/10.3740/MRSK.2019.29.6.385 인용 PDF KSCI