PB/ITO-PET柔性电致变色薄膜制备及性能研究

柔性电致变色器件具有体积小、重量轻、可弯曲等优点,在可穿戴设备、曲面显示器、节能及自适应伪装等领域具有潜在应用前景。本工作以铁氰化钾、氯化钾、无水氯化铁为原料,采用电沉积方法在ITO-PET柔性基底上沉积普鲁士蓝(PB)制得PB/ITO-PET电致变色薄膜,并利用扫描电子显微镜、紫外光谱仪、电化学工作站对PB/ITO-PET电致变色薄膜微观结构和电化学性能进行分析表征。结果表明,电沉积时间为200 s时得到的PB/ITO-PET电致变色薄膜在700 nm波长处光吸收率达到0.755,且PB/ITO-PET电致变色薄膜可在较低电压(0.6 V/-0.3 V)下实现着色和褪色。其光调制范围为68%,着色/褪色响应时间分别为9 s/8 s,着色效率为108 cm2/C。PB/ITO-PET电致变色薄膜经1000次着色-褪色循环后光调制范围为68%,着色效率为100.3 cm2/C。PB/ITO-PET电致变色薄膜500次弯曲,着色效率为105.5 cm2/C,并经1000次着色-褪色循环后着色效率为91 cm2/C,光调制范围为65%。利用ITO-PET为离子存储层(对电极)、凝胶电解质和PB/ITO-PET为工作电极组装得到柔性电致变色器件,其光调制范围为53%,着色/褪色响应时间分别为13 s/18 s。     

膜厚对直流反应磁控溅射沉积NiO薄膜的结构与电致变色性能的影响

采用直流反应磁控溅射法在FTO玻璃基片上沉积了不同厚度的氧化镍(NiO)薄膜.用X射线衍射仪(XRD)、场发射扫描电子显微镜(SEM)、X射线光电子能谱仪(XPS)、台阶仪、紫外可见分光光度计、电化学工作站,研究了NiO薄膜厚度对其微观结构、形貌,以及电致变色性能的影响.结果表明,随着溅射时间增加,NiO薄膜厚度增加,试样的初始态可见光谱透过率逐渐降低,(200)晶面的XRD衍射峰强度逐渐增加;以1 M KOH溶液作为电解质,随着NiO薄膜厚度增加,薄膜电荷储存量逐渐增大.NiO薄膜厚度为920 nm的试样着色效率最高,达到了23.46 cm2/C;80 nm厚度的薄膜试样光学调制幅度最大,波长550 nm处为40.85％.薄膜越厚,着、褪色时间越长;所有试样着色时间均大于褪色时间,80 nm厚度的薄膜试样的着色、褪色时间最快,分别为4.47 s和2.28 s.     

工艺参数对磁控溅射WO_3薄膜电致变色性能的影响

本文采用磁控溅射法制备了用于电致变色器件的WO_3薄膜,用X射线衍射仪(XRD)、场发射扫描电镜(FE-SEM)、紫外-可见分光光度计(UV-Vis)对其物相组成、微观形貌以及电致变色性能进行了表征。结果表明:在溅射压强为2 Pa、氩氧比为60:20时所制备的WO_3薄膜厚度适中,且有利于离子的嵌入/脱出,而以此薄膜制备的电致变色器件光调制范围最大,褪色时间最短,着色效率达82.9 cm~2/C。     

反应磁控溅射氧化钨电致变色薄膜厚度对结构、性能的影响

采用脉冲直流反应磁控溅射镀膜方法在FTO透明导电玻璃上制备厚度分别为50nm、100nm、150nm、200nm、250nm和300nm的氧化钨薄膜;采用XRD( X射线衍射) 和AFM（原子力显微镜）分析薄膜着色前后晶体结构和表面形貌的变化;采用电化学工作站和可见-近红外分光光度计对薄膜的循环伏安特性和光学性能进行测试。研究获得：不同厚度氧化钨薄膜均为结晶态,具有单斜晶系结构;随着薄膜厚度增加,薄膜结晶程度逐渐增加;薄膜着色/褪色循环中,不同厚度氧化钨薄膜均发生单斜晶系WO2.92与立方晶系WO3的可逆转变,产生晶格应变,并且随厚度增加,薄膜晶格应变先减小后增大,薄膜厚度为250nm时变色前后晶格应变最小,厚度进一步增加至300nm薄膜着色产生应变明显增大。在相同驱动电压下,随薄膜厚度增加,光学调制幅度（550nm）、着色效率先增大后减小,厚度为250nm时获得最大调制幅度76.01%,和着色效率21.04cm2/C;当厚度进一步增加至300nm时,薄膜褪色态透过率降低到49.30%后无法继续褪色,着色效率也开始下降。使用XPS进一步分析了薄膜着、褪色状态下W元素的化学态,发现300nm薄膜褪色后一部分W5+无法转变成W6+,导致薄膜仍为蓝色。     

电致变色器件中WO3薄膜厚度的选择

WO3(三氧化钨)薄膜厚度的选择对电致变色器件性能有至关重要的作用。通过TFCalc软件理论计算WO3薄膜褪色态、着色态透过光谱及其光学调制幅度变化;通过在FTO(氧化锡掺氟)玻璃上制备氧化钨薄膜,研究分析不同厚度氧化钨晶体结构与光学调制幅度相关性。对比研究发现:WO3厚度的选择应根据着色态透过率和实际的光学调制幅度确定,光学理论计算WO3薄膜的调制幅度有一定的局限性,这与晶态WO3薄膜的结构发生变化有关。     

乙醇胺强化解离WO_(3)·H_(2)O微米片制备柔性WOx电致变色器件EI北大核心CSCD

WO_(3)电致变色器件具有变色响应时间短、光学对比度高等优点,在汽车后视镜、智能窗等领域具有重要应用。近年来,随着可穿戴电子设备的迅速发展,柔性WO_(3)薄膜的制备成为柔性电致变色器件领域的研究热点。但WO_(3)结晶温度较高,而受聚合物衬底可耐受温度的限制,通常需要采用磁控溅射、电子束蒸镀等真空气相沉积技术制备晶态柔性WO_(3)薄膜。此技术对设备要求高,且所制备的薄膜结构较致密,不利于电解液的渗透和电解质离子的快速脱嵌。采用液相回流化学法预合成了结晶态WO_(3)·H_(2)O微米片粉体,首次采用乙醇胺等胺类分子使WO_(3)·H_(2)O强化解离为高度分散的纳米粒子胶体溶液,经旋转涂覆液相成膜技术制备成柔性晶态WO_(x)薄膜并应用于柔性电致变色器件。机理研究表明,胺基官能团与WO_(3)·H_(2)O微米片的强界面相互作用产生的电荷斥力使其迅速解离。所制备的柔性WO_(x)电致变色器件的着色和褪色时间分别为5.9 s和5.4 s,着色效率最高可达146.7 cm^(2)/C,经200次弯折后仍具有较好的性能。     

氧化石墨烯复合TiO2-B薄膜的制备及其电致变色性能

目前具有一维纳米结构的TiO₂薄膜在电致变色领域应用主要受限于材料光调制幅度小、响应时间长、循环稳定性差等缺点。为了解决上述问题,本文采用沉积法将B型二氧化钛纳米管（TiO₂-B）与氧化石墨烯复合,以TiO₂粉末为原料,采用水热法得到钛酸纳米管后,利用沉积法在氟掺杂的氧化锡玻璃（FTO）基底上制备了高透明度、大光调制范围以及优良循环性能的氧化石墨烯复合B型二氧化钛纳米管电致变色薄膜（GO/TiO₂）。借助XRD、XPS、Raman、FESEM、HR-TEM等分析手段研究了氧化石墨烯用量对GO/TiO₂复合薄膜电致变色性能的影响。研究结果表明,当GO与钛酸纳米管的质量比（GO/钛酸）为7％时,GO/TiO₂复合薄膜离子扩散系数为1.46×10^-8cm²/s,着色效率值为38.1cm²/C,具有良好的电致变色性能。在-1.6V、633nm处,GO/TiO₂电致变色薄膜的光调制幅度可达77％,GO/TiO₂薄膜的着色和漂白时间分别为28.6s和4.8s,100次循环后的光调制幅度保持率为96.1％。     

钒取代多钨酸盐/中性红复合膜的制备及其电致变色性能研究

采用层接层技术将Dawson结构钒取代型多酸K_7P_2W_(17)VO_(62)·18H_2O(P_2W_(17)V)和有机染料中性红(NR)构筑成复合膜材料。利用紫外-可见吸收光谱、扫描电镜和循环伏安法对复合膜的形貌及氧化还原性质进行了表征,使用电化学工作站和紫外-可见吸收光谱联机对复合材料的电致变色性能进行了研究。通过数据得知,K_7P_2W_(17)VO_(62)·18H_2O(P_2W_(17)V)和中性红成功复合,且复合材料具有良好的电致变色性能,光反差为14.68%,着色时间为6.63 s,褪色时间为3.26 s,最大着色效率达到222 cm2/C,实现了粉色到深蓝色之间的可逆颜色变化以及可调颜色的电致变色。     

有机硅改性聚甲基丙烯酸甲酯一聚苯胺复合材料的制备及其电致变色性能研究

本文采用溶液聚合法及乳液聚合法合成了可溶性聚苯胺,用光电子能谱、X－射线衍射对其本征态及掺杂态的结构进行了表征。以甲基丙烯酸甲酯－甲基丙烯酰丙基三甲氧基硅烷共聚物为基体,用溶液复合法制备了聚苯胺复合电致变色膜,并采用扫描电镜、循环伏安法等对其结构和电致变色性能进行研究。结果表明复合电致变色膜在稳定态时仅出现第二氧化峰,在外加电压作用下其颜色在绿色至蓝黑色之间可逆变化。共聚物中含有偶联剂组分可以提高电致变色膜与ITO导电玻璃基底的粘结性及改善复合电致变色薄膜的耐溶剂性能。     

反应磁控溅射氧化钨电致变色薄膜结构与性能

采用脉冲直流反应磁控溅射镀膜方法在透明导电玻璃FTO(SnO_2:F)上制备厚度分别为50、100、150、200、250和300 nm的WO_3薄膜。分析了薄膜着色前后晶体结构和表面形貌的变化,对薄膜的循环伏安特性和光学性能进行测试。结果表明:不同厚度氧化钨薄膜均为结晶态,具有单斜晶系结构;随着薄膜厚度增加,薄膜结晶程度逐渐增加;薄膜着色/褪色循环中,不同厚度的WO_3薄膜均发生单斜晶系WO_(2.92)与立方晶系WO_3的可逆转变,产生晶格应变,并且随厚度增加,薄膜晶格应变先减小后增大,薄膜厚度为250 nm时,变色前后晶格应变最小,厚度增加至300 nm薄膜时,着色产生应变明显增大。在相同驱动电压下,随薄膜厚度增加,光学调制幅度(550 nm)、着色效率先增大后减小,厚度为250 nm时获得最大调制幅度76.01%和着色效率21.04 cm~2/C;当厚度进一步增加至300 nm时,薄膜褪色态透过率降低到49.30%后无法继续褪色,着色效率也开始下降。使用XPS分析了薄膜着、褪色状态下W元素的化学态,发现300 nm薄膜褪色后一部分W~(5+)无法转变成W~(6+),导致薄膜仍为蓝色。     

Effect of Ar/O2 ratio on double-sided electrochromic glass performance

This paper reports the qualities of WO₃ film and NiO film added to a counter electrode and their use in a double-sided electrochromic glass device. A mixture of argon and oxygen gasses with ratios of Ar/O₂ of 1.5, 2, 3, and 5 were used for the deposition of the working electrode of WO₃ film for EC glass. The structure of double-side EC glass consists of glass/ITO/NiO/electrolyte/WO₃/ITO/glass/ITO/WO₃/electrolyte/NiO/ITO/glass layers. The working electrode of WO₃ film controls the color presented, the applied voltage controls the color depth, and the counter electrode controls the transparency in the bleached state. The double-sided EC glass with double WO₃ films and double NiO films have faster coloration/bleaching rates than do single-sided EC glass. A mixture of Ar/O₂ ratio of 3.0 has the best coloration/bleaching property of the ratios tested. Compared to the single-sided EC glass, the double-sided EC glass has lower transmittance of about 72% and 6% than the 78% and 12% during coloration and bleaching states in the visible light region with +1.5 V and ?3.5 V applied.     

Electrochromic properties of porous NiO thin film as a counter electrode for NiO/WO3 complementary electrochromic window

Highly porous nickel oxide (NiO) thin films were prepared on ITO glass by chemical bath deposition (CBD) method. SEM results show that the as-deposited NiO film is constructed by many interconnected nanoflakes with a thickness of about 20 nm. The electrochromic properties of the NiO film were investigated in a nonaqueous LiClO₄–PC electrolyte by means of optical transmittance, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements. The NiO film exhibits a noticeable electrochromic performance with a variation of transmittance up to 38.6% at 550 nm. The CV and EIS measurements reveal that the NiO film has high electrochemical reaction activity and reversibility due to its highly porous structure. The electrochromic (EC) window based on complementary WO₃/NiO structure shows an optical modulation of 83.7% at 550 nm, much higher than that of single WO₃ film (65.5% at 550 nm). The response time of the EC widow is found to be about 1.76 s for coloration and 1.54 s for bleaching, respectively. These advantages such as large optical modulation, fast switch speed and excellent cycle durability make it attractive for a practical application.     

Logotype-selective electrochromic glass display

This paper describes a fabrication method of a logotype-selective electrochromic (EC) glass. The EC glass performance based on the sample size, WO₃ film thickness, and internal impedances under various applied voltages are also discussed. The logotype-selective electrochromic glass was fabricated by the sputter deposition process. Both working and counter electrode were coated with ITO/WO₃ films. The specific logotypes of “NCUT” and “NUU” can be displayed with positive and negative voltages applied to the EC glass. EC glasses of various sizes (1 cm², 4 cm², 9 cm², 25 cm², and 100 cm²) were also fabricated by sputter deposition process. When voltage (?3.5 V) was applied to the device, the active layer of the assembled device changed from almost transparent to a translucent blue color (colored). The average transmittance in the visible region of the spectrum for a 100 cm² EC device was 73% in the bleached state. The best device, with a 140 nm WO₃ active layer, had average transmittances in the colored and bleached states of 11.9% and 54.8%, respectively. Cyclic voltammogram tests showed that reproducibility of the colored/bleached cycles was good. Nyquist plots showed that increasing the device size decreased the current density, and the electrolyte impedance increased because of a low conductive electrolyte in the device.     

添加聚乙烯醇改善三氧化钨电致变色薄膜性能的研究

为改善三氧化钨薄膜的电致变色性能,采用钨粉过氧化聚钨酸溶胶-凝胶法制备了添加聚乙烯醇的三氧化钨电致变色薄膜.采用扫描电镜、紫外可见分光光度计和CHI电化学工作站分别测定和分析了三氧化钨薄膜的微观结构、光透过性能和循环伏安特性.结果表明,添加一定量的聚乙烯醇可使薄膜的结构更加平整,变色更为均匀;在着色态、褪色态下的光透过率之差达到60%以上,变色可调范围变大.电致变色可逆性能和光谱性能较不添加聚乙烯醇有所提高.     

Influence of Ag incorporation on the structural,optical and electrical properties of ITO/Ag/ITO multilayers for inorganic all-solid-state electrochromic devices

Indium tin oxide/silver/indium tin oxide (ITO/Ag/ITO, IAI) multilayer structures were prepared by DC magnetron sputtering as a conductive transparent electrode for inorganic all-solid-state electrochromic devices. A thin layer of silver (Ag) with various thicknesses was inserted between two layers of ITO films. The XRD and SEM results revealed that the microscopic morphology of Ag film was closely related to the thickness. Besides, the electrical and optical properties of the IAI multilayers were significantly influenced by the Ag layer thickness. The optimized IAI multilayers demonstrated the best combination of electrical and optical properties with a figure of merit of 54.05 (sheet resistance of 6.14 Ω/cm²and optical transmittance of 90.83%) when the Ag film was 10 nm thick. In order to evaluate the IAI multilayers as a transparent electrode for electrochromic applications, two ECDs with the structures of ITO/NiO_x/LiPON/WO₃/ITO and ITO/NiO_x/LiPON/WO₃/IAI were prepared, and their electro-optical properties were characterized by cyclic voltammetry (CV), chronoamperometry (CA) and spectroscopic measurements. Compared with ECD the pure ITO top electrode (ITO/NiO_x/LiPON/WO₃/ITO), the ECD with the IAI top electrode (ITO/NiO_x/LiPON/WO₃/IAI) presented a slightly smaller optical modulation amplitude, but a faster switching speed. All our findings indicate that the IAI multilayer structure is a promising alternative to the ITO thin film for inorganic all-solid state electrochromic applications.     

Flexible electrochromic device based on poly (3,4-(2,2-dimethylpropylenedioxy)thiophene)

In this study, the design, fabrication and characterization of a flexible electrochromic device based on indium tin oxide (ITO) coated polyethylene terephthalate (PET) plastic is discussed. The working electrochromic material film was poly (3,4-(2,2-dimethylpropylenedioxy)thiophene) (PProDOT-Me₂), while the counter layer of the device was vanadium oxide titanium oxide (V₂O₅/TiO₂) composite film, which serves as an ion storage layer. A solution type electrolyte was used as the ionic transport layer and was sandwiched between the working and counter layers. The device exhibited tuneable light transmittance between transparent and deep blue color, with a maximum contrast ratio at 580 nm wavelength. Other important properties, such as switching speed, life time, and coloration efficiency have been improved.     

Effect of laser power density on the electrochromic properties of WO3 films obtained by pulsed laser deposition

Pulsed laser deposition (PLD) was used to prepare tungsten trioxide (WO₃) films on ITO substrates with a varying laser power density of 4.0–5.5 W/cm². XPS indicated that when the laser power density decreased, the peak positions of the W 4f and O 1s orbits shifted slightly to low energy due to the difference in oxygen vacancies. As the laser power density decreased, W⁶⁺ gradually replaced the lattice position of O^2?, increasing oxygen vacancies in the lattice. The transmittance modulated values (ΔT) were over 44% at 830 nm, indicating strong absorption by the WO₃ thin films in the near-infrared ray. The switching time of the WO₃ thin films between bleached states and coloured states decreased as the laser power density increased due to the amorphous structure, morphology, and lower oxygen deficiency at a high power density. The high ΔT and very fast switching time of t_b (1.09 s) and t_c (6.01 s) demonstrated the excellent electrochromic (EC) properties of the WO₃ films prepared by PLD.     

Solid-state electrochromic devices using pTMC/PEO blends as polymer electrolytes

Flexible, transparent and self-supporting electrolyte films based on poly(trimethylene carbonate)/poly(ethylene oxide) (p(TMC)/PEO) interpenetrating networks doped with LiClO₄ were prepared by the solvent casting technique. These novel solid polymer electrolyte (SPE) systems were characterized by measurements of conductivity, cyclic voltammetry, differential scanning calorimetry and thermogravimetry.The incorporation of solid electrolytes as components of electrochromic devices can offer certain operational advantages in real-world applications. In this study, all-solid-state electrochromic cells were characterized, using Prussian blue (PB) and poly-(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT) as complementary electrochromic compounds on poly(ethyleneterphthalate) (PET) coated with indium tin oxide (ITO) as flexible electrodes. Assembled devices with PET/ITO/PB/SPE/PEDOT/ITO/PET “sandwich-like” structure were assembled and successfully cycled between light and dark blue, corresponding to the additive optical transitions for PB and PEDOT electrochromic layers. The cells required long cycle times (>600 s) to reach full color switch and have modest stability towards prolonged cycling tests. The use of short duration cycling permitted the observation of changes in the coloration-bleaching performance in cells with different electrolyte compositions.     

低阻高透柔性导电膜制作技术

介绍低阻高透柔性导电膜膜层结构以及膜层厚度配比,根据物质的理化性能(附着力、光学性能、电学性能等)进行搭配,导电层由ITO/Ag/ITO膜层组成,在导电层和柔性基底之间引入折射率膜层SiO_x,PET基材经过等离子设备预处理后,工艺室的阴极依次镀制SiO_X、ITO、Ag、ITO等膜系。按照控制变量法,通过对导电层以及折射层膜厚设计,经工艺调整得到市场所需指标产品。