WO3薄膜的电致变色特性研究

介绍了ＷＯ３电致变色薄膜的变色机理和制备工艺，对ＷＯ３薄膜的电阻率，结构，化学组玢，电化学特性和变性性能等特性进行了工艺，提出了ＷＯ３薄膜的一种新的锂化方法，这种方法对进一步研制全固态电致变色薄膜器件是十分关键的。     

全固态塑料电致变色器件

电致变色器件是一种典型的光学薄膜和电子学薄膜相结合的光电子薄膜器件,能够在外加低压驱动的作用下实现可逆的色彩变化。将电致变色材料制备在塑料衬底上,将极大地推动电致变色器件的应用。讨论了全固态塑料电致变色器件的制备工艺和电致变色特性,通过采用低压反应离子镀工艺分别在ITO塑料衬底上制备了WO3和NiO电致变色薄膜。采用高分子聚合物MPEO-LiClO4作电解质,制备plastic/ITO/WO3/MPEO-LiClO4/NiO/ITO/plastic透射型全固态塑料电致变色器件。在二电极电池石英盒中采用恒电位方式测试全固态塑料电致变色器件的电致变色特性,驱动电压为±3V。采用分光光度计直接测试透射光谱的变化,测试范围为300～900nm,经过十几次循环后达到稳定的变色,变色调制范围达到30%左右,器件样品显示出均匀深蓝色的电致变色效果。实验结果证明了所提出的全固态塑料电致变色器件的制备工艺的可行性。     

溶胶-凝胶法制备电致变色薄膜及器件的研究

用离子交换法制备ＷＯ３电致变色薄膜,并制备结构为ＷＯ３／ＬｉＣＯ４＋ＰＣ／ＴｉＯ２的夹层式半固态电致变色器件。测试了薄膜及器件的循环伏安特性曲线,研究了薄膜及器件在不同的扫描电压及扫描速率下的电致变色性能,并获得了ＷＯ３薄膜在导锂离子情况下的着色效率。实验证明,溶胶－凝胶法完全能够成为一种有效的制备大面积电致变色灵巧窗的方法。     

电解质浓度对氧化钨薄膜电致变色性能的影响规律及作用机理

电解质为电致变色器件的变色提供离子,是器件中不可缺少的一部分。然而,目前对电解质层的研究主要集中在复合电解质和极限浓度,少有探究电解质浓度对电致变色性能的影响规律和机理,尤其是循环稳定性。因此,本文系统研究了高氯酸锂(Li Cl O₄)电解质浓度(0.1、0.5、1.0、2.0 mol/L)对氧化钨(WO₃)薄膜循环前后电致变色性能的影响,及对其循环稳定性的作用机理。结果表明,当Li Cl O₄浓度为1.0 mol/L时,WO₃薄膜表现出最短的着色/褪色时间,初始电荷储存量高达25.2 m C·cm^-2,6000圈伏安(CV)循环后,衰退率仅为25.4%,表现出最佳的循环稳定性。该研究详细介绍了电解质浓度对WO₃薄膜电致变色性能及其循环稳定性的影响规律及作用机理,对WO₃基电致变色器件的设计和制备具有重要的指导意义。     

基于Cr/Ag/WO_(3)薄膜的柔性反射式电致变色器件EI北大核心CSCD

柔性反射式电致变色器件在电子纸显示、伪装、智能变色表面等领域应用前景广阔,但仍存在柔性差、对比度低、稳定性不佳等问题。本工作采用电子束蒸发法在玻璃和柔性PET衬底上制备了Cr/Ag/WO_(3)(CAW)结构无铟反射式电致变色薄膜。CAW薄膜具有高反射率和低面电阻,其可见光平均反射率高达89.1%,面电阻仅为1.2Ω/□。在电致变色性能方面,CAW薄膜展示出快着色及褪色响应时间(分别为9.3 s和2.0 s)、高达83.0%(564 nm)的反射光学对比度、大范围的反射颜色调节(>40 nm)和良好的电化学循环稳定性(>4500次)。此外,CAW薄膜具有良好的衬底兼容性,我们制备了柔性CAW薄膜并组装了图案化柔性电致变色器件,柔性薄膜在弯折2000次后性质基本无衰减,对比度达83.2%(574 nm),器件在不同电压作用下实现了丰富的反射颜色动态调控。这些结果将为高性能柔性反射式电致变色器件构建提供简单有效的指导,在新型显示技术领域有一定应用潜力。     

液氮冷却法全无机智能窗器件的制备及其性能研究

为降低溅射过程中摹片温度的上升,进而成功制备非晶多孔、纳米微晶态电致变色薄膜和非晶态离子导电薄膜,介绍了一种配置于磁控溅射设备的液氮冷却装置.利用该装置制备了由WO3、NiOx和LiNbO3 薄膜组成的单基片全无机电致变色智能窗器件.采用分光光度计对该器件的电致变色性能进行了测试,并计算了它的漂白和着色态在400 nm到800 nm波长范围内的平均透射率.实验结果表明,经过50次循环后,该器件的漂白和着色态的平均透射率分别为61.5%和5.5%.X射线衍射和扫描电镜(SEM)图像显示,组成该器件的WO2、NiOx和LiNbO3薄膜分别为非晶多孔、纳米微晶和非晶态结构.     

长寿命导H^＋全固态电致变色器件的研究

研究了导Ｈ＾＋离子全固态电致变色器件性能退化摧在机制，发现有两个因素导致器件性能退化，在器件褪色过程中，存在于ＷＯ３薄膜中的水份将导致ＯＨ＾－在ＷＯ３中积累而在其中产生碱性环境，ＷＯ３溶于碱性环境而生成钨酸盐，在较高电压作用下Ｈ２Ｏ电解释放出气体Ｈ２和Ｏ２而使膜层剥落，通过改进器件结构和改善制备工艺条件，获得了光学密度高达０．５，着色／漂白（Ｃｏｌｏｒ／Ｂｌｅａｃｈ）循环次数高达１０＾６以上的性能     

用作电致变色器件的LiNbO_3离子导体薄膜的研究

采用射频溅射方法制备用作电致变色器件的ＬｉＮｂＯ３薄膜，利用频率外推法和Ｗａｎｇｎｅｒ极化法对所沉积的ＬｉＮｂＯ３离子导体薄膜的离子电导率进行了测试和计算，给出了薄膜的光谱特性，分析和讨论了薄膜制备工艺对薄膜结构和离子电导率的影响和作用。     

新型窗帘式WO3基电致变色器件设计与制备

采用磁控溅射法制备氧化钨(WO₃),基于电流驱动模型设计制备无需对电极层的新型窗帘式电致变色器件,并对器件的边框、WO₃薄膜的最佳厚度和离子储存区尺寸进行了系统优化。结果表明,制备得到的WO₃薄膜在550 nm波长处的调制率高达78%,1000圈循环伏安曲线测试后电荷储量衰减率仅为3.5%;设计的窗帘式器件显色区域高度可控,且消除了对电极对器件性能的影响。该研究为电致变色器件结构创新提供了新思路。     

WO3/Ag复合薄膜的制备及其电致变色性能

通过水热法在导电玻璃上合成WO_3纳米块,利用电沉积技术在WO_3纳米块上负载不同含量(20 s、50 s、80 s)的Ag纳米粒子,成功制备出WO_3/Ag复合薄膜.通过X射线衍射分析、扫描电子显微镜与能谱对WO_3/Ag复合薄膜进行表征,利用电化学测试与光谱测试,得到电致变色可逆性、响应时间、着色效率和光谱透过率等参数,并对其电致变色性能进行分析.结果表明,对比单一WO_3纳米块薄膜的电致变色性能,WO_3/Ag复合薄膜的电致变色性能显著增强.同时研究了不同Ag纳米粒子含量对WO_3/Ag复合薄膜电致变色性能的影响,研究表明沉积50 s的WO_3/Ag复合薄膜具有最优异的电致变色性能.     

Highly uniform electrochromic tungsten oxide thin films deposited by e-beam evaporation for energy saving systems

In the last few decades, there has been a surge of interest in using tungsten oxide thin films as an active layer of electrochromic device. These devices have several practical applications such as smart window of buildings and automobile glazing for energy saving. The main objective of this work was to construct highly homogeneous and uniform e-beam evaporated amorphous WO_3-x based films into electrochromic devices, which were fully characterized for switching speed, coloration efficiencies and cycling voltammetry responses. Fabricated devices contain indium doped transparent oxide coated glass as the transparent conductive electrode, ～200?nm thickness of WO_3-x as the cathodically coloring material and a lithium perchlorate based conducting gel electrolyte. X-ray diffraction patterns indicate that all as-deposited films are amorphous. Experimental results showed that both solid and liquid electrolyte electrochromic devices are initially very transparent that exhibit perfect optical modulation and coloration efficiency (up to 68.7?cm²/C and 52.6?cm²/C at 630?nm, respectively) due to easier intercalation of the Li⁺ within their structure. One of the more significant findings to emerge from this study is that e-beam coated electrochromic devices based on tungsten oxide thin films showed superior performance among to other coating methods. Therefore, excellent reversibility of color change behavior is attractive for pertinent use in electrochromic energy storage devices.     

Electrochromic and photoluminescence properties of cobalt oxide thin films prepared by spray pyrolysis

Cobalt oxide thin films were prepared by a facile spray pyrolysis technique, using a perfume atomizer with an aqueous solution of hydrated cobalt chloride salt with a molar concentration of 0.025?M as a source of cobalt. The films were deposited onto glass substrates at temperature of 350?°C. The structural, morphological, and electrochromic properties of the obtained films were studied. It was found from X-ray diffraction analysis that the films were polycrystalline in nature with spinel-type cubic structure and preferred orientation along [111] direction. The Scanning Electron Microscopy images revealed a porous structure with the average grain size around 200?nm. The cyclic voltammetry measurements revealed that Cobalt oxide thin film is an anodically coloring electrochromic material with a transmittance variation in the visible range of 31%, and a fast response time (about 2?seconds) and a good cycling stability. These electrochromic performances make cobalt oxide thin film an attractive material for using as an anodic electrochromic material in smart windows devices. The photoluminescence spectra exhibited a strong emission in the visible region confirming the good crystallinity properties of Co₃O₄ thin films.     

旋涂法制备WO3薄膜电致变色性能

"智能窗"大规模推广顺应可持续发展潮流,三氧化钨(WO_3)是生产"智能窗"的一种重要电致变色材料,但调控WO_3薄膜电致变色性能机制仍待进一步研究。采用旋涂法制备WO_3薄膜,重点研究了溶液浓度和旋涂次数对调控WO_3薄膜电致变色性能的影响。通过表面轮廓仪测量薄膜厚度,X射线衍射(XRD)测量薄膜结晶情况,原子力显微镜(AFM)和扫描电子显微镜(SEM)分析薄膜表面形貌,光谱仪测量薄膜初始态、着色态和褪色态的透射率。实验结果表明,随着溶液浓度增加(0. 2～1. 0 mol/L),薄膜厚度从9. 7 nm增加到33. 3 nm,透射率调制能力从0%提升到37. 0%;多次旋涂薄膜厚度线性增长,线性拟合优度(R~2)达0. 98,5次旋涂后透射率调制能力达51. 3%。改变溶液浓度和旋涂次数都是调控薄膜透射率调制能力的有效手段,精准调控薄膜透射率调制能力对设计不同应用场景的电致变色器件具有重大意义。     

新型无铟透明导电-电致变色双功能MoO_3/Ag/MoO_3薄膜的制备及性能研究

研制了集电致变色和透明导电功能为一体的MoO_3/Ag/MoO_3(MAM)双功能薄膜。MAM薄膜采用电子束热蒸发技术在室温下制备。作为透明电极,MAM薄膜显示出良好的光电性能,可见光平均透过率为59.4%,方块电阻为12.2Ω/□。作为电致变色材料,MAM薄膜具有较快的响应时间(着色时间4.3 s,褪色时间11.1s),25%的光学对比度(528 nm),良好的稳定性(100次循环),以及较高的着色效率(40.5 cm~2·C~(-1)),在已报道的MoO_3着色效率中处于较高的水平。     

An electrochromic device (ECD) cell characterization on electron beam evaporated MoO3 films by intercalating/deintercalating the H+ ions

Thin films of molybdenum oxide (MoO₃) is one of the most interesting layered intercalation materials because of its excellent application in solid state batteries, large-area window and display systems. In recent years there has been considerable interest in variable transmittance electrochromic devices (ECD) based on Li⁺, H⁺ and K⁺ intercalation in transition metal oxide (MoO₃) thin films. In the present investigation, thin films of MoO₃ were prepared by electron beam evaporation technique on microscopic glass and fluorine doped tin oxide (FTO) coated glass substrates for the application in electrochromic device cells. The compositional stoichiometry of the films was studied by X-ray photoelectron spectroscopy (XPS). The electrochromic nature of the films has been analyzed by inserting H⁺ ions from the H₂SO₄ electrolyte solution using the cyclic-voltammetry (CV) technique. We studied the electrochromic device cells (ECD) incorporating an evaporated MoO₃ thin films as electrochromic layers. The devices exhibit good optical properties with low transmittance values in the colored state, which make them suitable for large-area window applications. The maximum coloration efficiency of the cell was observed at about 70 cm²/C.     

中频孪生磁控溅射WO3薄膜及变色性能研究

采用先进的中频孪生非平衡磁控溅射技术,以金属钨为靶材,制备非晶态WO3电致变色薄膜。用X射线衍射(XRD)、X射线光电子能谱(XPS)、紫外分光光度计等测试手段分析薄膜的结构、表面形貌、成分以及透射光谱特性。研究了氧气流量比及热处理温度对WO3薄膜变色性能的影响。结果表明,中频孪生非平衡磁控溅射技术是制备WO3变色薄膜的一种有效方法;室温条件下沉积获得的原始态薄膜为非晶态WO3;提高氧气流量比和适当热处理温度能有效改善薄膜的电致变色性能。实验中在较高氧气流量比,200℃热处理条件下制备的薄膜在380~780 nm的可见光范围内着色态和褪色态平均透光率差值高达50%以上,表现出较好的电致变色性能。     

DC magnetron sputtered Mo-Ti oxide films for color neutral electrochromic devices

Mo-Ti oxide films with compositions ranging from MoO₃ to TiO₂ were prepared by reactive DC magnetron sputtering using a newly developed high-rate technique with interacting plasma zones. Optical and electrochemical measurements showed that an increase of the Ti content yielded increased electrochemical stability, decreased coloration efficiency, and increased potential for electrochromic coloration. The films have interesting properties for color-neutral electrochromic devices. Paper presented at the 2nd Euroconference on Solid State Ionics, Funchal, Madeira, Portugal, Sept. 10–16, 1995     

An All-Thin-Film Electrochromic Device Composed of MoO3--LiBSO--NiOx Multilayer Structure

An all-thin-tilm （ATF） electrochromic device for modulating the optical transmittance is manufactured using magnetron sputtering. The devices consists of MoO3 as the main electrochromic layer, LiBO2 ＋Li2SO4 （LiBSO） as the ion conductor layer, and NiOx as the complementary electrochromic layer. Glass covered with indium tin oxide （ITO） is used as the substrate and the ITO film is used as the bottom electrode. The ITO film deposited on the top of the devices is used as the other electrode. The structure and morphology of the films are characterized by x-ray diffraction （XRD） and scanning electron microscopy （SEM）. The devices exhibit good optical properties with low transmittance values in the coloured state, and the optical modulation is measured by spectrophotometer in the wavelength range from 400 to 800nm. The average visible light transmittance reaches 50.2% and 3.7% in bleached and coloured state, respectively. The results indicate that such a monolithic system has great potential to be applied in smart windows.     

Transparent conductive electrodes for electrochromic devices: A review

This paper reviews the optical and electrical performance of thin films that are useful as transparent electrodes in electrochromic devices. The properties of certain heavily doped wide-bandgap semiconductor oxides (especially In₂O₃:Sn) and of certain coinage metal films are discussed.