聚苯胺基柔性电致变色器件的设计与研制

采用循环扫描伏安法在导电聚酯薄膜上聚合出聚苯胺(PAN)膜,考察了PAN膜的聚合过程及其表现出的电致变色行为;设计并制备了基于PAN膜的反射型柔性电致变色器件,考察了该器件反射光谱的电压响应特性.结果表明,电聚合过程中,在-0.2～2.0V电压范围内,PAN膜的颜色在黄绿-绿-深蓝之间循环变化;在-0.4v～1.8v电压范围内,研制的基于PAN膜的反射型柔性电致变色器件的反射率及其峰值随着外加电压的改变而变化,表现出较好的电压响应特性.     

基于单片机便携式颜色自适应识别电路的设计

为解决电致变色器件的颜色变化受外界环境颜色控制的问题,设计了一种基于单片机的便携式颜色自适应识别电路。与传统颜色识别电路相比较,该电路利用数字式的颜色传感器来获取外界环境颜色,产生的数字颜色信号易于单片机进行处理。在电路中,下位机部分主要负责获取电致变色器件变色参数及控制电致变色器件的颜色变化;而上位机部分主要负责把下位机获取的电致变色器件变色参数进行电压到颜色的曲线拟合,并通过蓝牙通信把拟合曲线参数传递给下位机。结果表明,该电路能自动根据环境颜色提供-4～4 V范围步进为0.1 V的电压来驱动电致变色器件的颜色显示,与传统的颜色识别电路设计相比,识别的精度和速度都得到了明显改善。     

WO 3薄膜电致变色器件的响应时间测试及其改善方案

电致变色(Electrochromism,EC)器件,具有工作电压低、多稳态、静态无功耗、变色功耗低、透光度/反射度连续可调等特点.WO3制作的电致变色器件存在响应时间过长、光学调制幅度较低等问题.为了能够进一步缩短响应时间,本文使用WO 3作为变色层的材料并制备电致变色器件,研究了不同氩氧流量比下对WO 3薄膜的影响...     

混合氧化物电致变色器件

本文考察了WO3：TiO2混合氧化物电致变色的机理及WO3：TiO2厚度不同的器件的电致变色特性。结果表明：WO3：TiO2混合氧化物电致变色的过程符合电化学氧化还原反应,在电场作用下,着色前后离子价态发生可逆变化,着色后膜层处于混合价态离子共存状态。适当的TiO2掺杂量可以改善WO3：TiO2电致变色器件的变色特性、响应时间和器件寿命。     

一种新型互补溶液型电致变色器件的研究

用TiCl4作为钛离子源，发现Ti^4＋离子和紫罗精之间具有互补效应。利用这种互补溶液，设计了一种结构简单的电致变色器件。施加不同的外加电压，可以调节电致变色器件的光强透过率以及器件的颜色。去掉外加电压，电致变色器件迅速变为透明态，具有自擦除效果。紫外-可见分光光度计表征表明，器件透过率在600nm附近可以由80％下降到20％；用自己设计的光电响应测试系统，测得电致变色器件退色时间小于2S，在智能窗、纸张型电子书等方面具有使用价值。这种互补溶液体系是将现有的纯有机溶液互补体系扩展到无机体系中，并且得到了一种新的廉价的电子D-A（Donor-Accept）对，为新型溶液型电致变色器件的实用化提供了新的技术途径。     

矩阵选址电致变色显示单元

本文报导一种具有自选址能力的矩阵电致变色显示单元。基于溅射的氧化铱膜(SIROF)和氧化钽滞回背面电极的单元有类似其他SIROF显示器件的电致变色参数(即响应时间、工作电压及对比度),而且还有短路存储和电压阈。原则上说,存储和电压阈足够使大屏幕电视象素尺寸电致变色显示板得以多路并联使用。     

磁控溅射法制备氧化钨薄膜的膜层微观结构对电致变色性能的影响北大核心CSCD

利用磁控溅射法,在不同工作压强下制备了氧化钨(WO_3)薄膜,研究了工作压强对WO_3膜层微观结构的调控作用,并研究了WO_3膜层微观结构对其电致变色性能的影响。研究结果表明,制备的WO_3薄膜属于非晶相,表面呈峰状结构;随着工作压强的增大,WO_3薄膜膜层微观结构变疏松,电致变色响应时间和循环寿命均减短;在最佳膜层微观结构下,WO_3薄膜光学密度可达0.64,循环寿命达1500周。     

掺杂硫酸浓度对聚苯胺膜性能的影响

采用循环伏安法在镍基底上制得聚苯胺(PAn)膜,研究了硫酸掺杂剂的浓度对PAn膜聚合过程、电致变色性能、微观形貌及结构的影响。结果表明,在参比电压为–0.2~+1.4 V范围内,该膜的颜色可以在黄绿–绿–深蓝间可逆变化;在0.4 mol/L的掺杂H2SO4浓度下聚合反应平稳进行,所得PAn为晶态纳米纤维网结构。过低或过高的酸度下,PAn几何尺寸增大,为非晶态纳米颗粒,其电致变色性能变差。     

电真空器件

0622830蓝光OLED的掺杂研究[刊,中]/季兴桥//量子电子学报．—2006,23(3)．—416-419(L) 0622831利用位置敏感型光电倍增管测量光斑漂移的定标方法[刊,中]/马晓珊//量子电子学报．—2006,23(3)．—311-315(L) 0622832聚合物全固态电致变色器件的制备及性能[刊,中]/张公正//功能材料与器件学报．—2006,12(3)．—220- 224(G)使用乙烯-乙烯醇共聚物/聚吡咯复合膜和聚醚基氨酯/LiClO_4电解质制成全固态电致变色器件。当加上1．0～2．5V的直流电压时,器件颜色由黄色变成棕(蓝)色。详细讨论了器件的UV/VIS光谱变化、掺杂/不掺杂过程的响应时间以及电解质浓度对变色过程的影响。结果显示电致变色器件在800nm时,发生掺杂/不掺杂过程变化有短的响应时间和大的透过率差。参14     

氧化镍膜的电致变色机理

氧化镍是一种很好的阳极电致变色材料,用作背电极与阴极电致变色材料相配合,制作的电致变色显示器件可避免一般电致变色显示器件中背电极所产生的副作用。但迄今为止,氧化镍膜在水溶液电解质中伴随着氧化还原电化学反应所产生的一系列结构变化和电致变     

红外发射率控制方法及机理研究

红外发射率的控制具有广泛的用途,根据电磁波理论,讨论了物体表面的发射率与折射率的关系,折射率大的物体发射率低.电致变色材料是一种可控制其表面折射率和发射率的材料.以氧化钨为例探讨了发射率的控制方法.利用电场对三氧化钨薄膜进行离子和电子的共注入和共抽取,三氧化钨中的载流子浓度发生了变化,折射率和红外发射率也发生了变化.     

基于辐射对比度的变发射率舰船的红外隐身研究

利用固定发射率的红外隐身涂料无法实现全天候舰船红外隐身。以小于0.04的目标与背景的辐射对比度作为红外隐身的评判标准,通过计算分析目标与背景的红外特征模型,得到了实现红外隐身所需的目标表面发射率变化范围,提出利用电致变色材料来改变目标表面的平均发射率。与固定发射率的普通红外隐身涂料相比,改变发射率后的红外隐身涂料的隐身效率有了很大的改善,基本能满足目标的全天候红外隐身要求。     

High performance black-to-transmissive electrochromic device with panchromatic absorption based on TiO2-supported viologen and triphenylamine derivatives

A novel black-to-transmissive electrochromic device based on TiO₂-supported viologen and triphenylamine derivatives was designed and constructed via the absorption-complementary approach. In the device, cathodically coloring electrochromic material 1,4-bis[((N-phosphono-2-ethyl)-4,4′-bipyridinium)-methyl]-benzene tetrachloride acted as working electrode and novel anodically coloring electrochromic material (4-((4-(dimethylamino)-phenyl)(4-methoxyphenyl)-amino)-benzyl) phosphonic acid acted as counter electrode. The assembled electrochromic device achieved panchromatic absorption over entire visible spectrum with almost zero transmittance in colored state. The optical contrast (ΔT) of the device realized in this work was comparable to the highest value (60%) among all reported black-to-transmissive ECDs. Furthermore, excellent cycling stability was achieved, which maintained almost 80% of the initial ΔT value at 570 nm after continuous 100,000 switchings. These outstanding comprehensive electrochromic performances potentially make this device a promising candidate for electrochromic device applications.     

A new electrochromic copolymer based on dithienylpyrrole and EDOT

A new compound, namely diethyl 2,5-di(thiophen-2-yl)-1H-pyrrole-3,4-dicarboxylate (1), was copolymerized with 3,4-ethylenedioxythiophene (EDOT) via electrochemical method. The copolymer exhibits multicolor electrochromic property: It is found that the copolymer, poly(1-co-EDOT), has a specific optical band gap (1.71 eV) to reflect and/or transmit reddish brown color in the neutral state, and it can be switched to reddish orange, orange, yellowish green and blue colors upon oxidation in a low switching time (1.0 s). Importantly, these colors are essential for camouflage and/or full color electrochromic device/display applications. In addition to these, the obtained copolymer has a coloration efficiency of 173 cm²/C at 500 nm.     

Photoactivated birefringent liquid-crystal light valve for color symbology display

Aphotoactivated liquid-crystal projection display device that is based upon the field-effect mode of the liquid crystal has been built and tested. The device displays high-resolution dynamic color symbology by means of the optical birefringence of the liquid crystal. The colors that can be displayed simultaneously are white (with gray scale), blue, green, yellow, and magenta on a dark field. The imaging light power required to excite the device varies from 30-900 µW/cm²at 525 nm and the resolution obtained at an MTF of 50 percent is 40 lines/mm. The basic construction of the device is similar to the dynamic scattering photoactivated liquid-crystal light valve.     

On‐Substrate Preparation of an Electroactive Conjugated Polyazomethine from Solution‐Processable Monomers and its Application in Electrochromic Devices

An electroactive polyazomethine is prepared from a solution processable 2,5‐diaminothiophene derivative and 4,4′‐triphenylamine dialdehyde by spray‐coating the monomers on substrates, including indium tin oxide (ITO) coated glass and native glass slides. The conjugated polymer was rapidly formed in situ by heating the substrates at 120 °C for 30 min in an acid saturated atmosphere. The resulting immobilized polymer is easily purified by rinsing the substrate with dichloromethane. The on‐substrate polymerization is tolerant towards large stoichiometry imbalances of the comonomers, unlike solution step‐growth polymerization. The resulting polyazomethine is electroactive and it can be switched reversibly between its neutral and oxidized states both electrochemically and chemically without degradation. A transmissive electrochromic device is fabricated from the immobilized polyazomethine on an ITO electrode. The resulting device is successfully cycled between its oxidized (dark blue) and neutral (cyan/light green) states with applied biases of +3.2 and ‐1.5 V under ambient conditions without significant color fatigue or polymer degradation. The coloration efficiency of the oxidized state at 690 nm is 102 cm² C^?1.     

A Dual-Mode Electrochromic Platform Integrating Zinc Anode-Based and Rocking-Chair Electrochromic Devices

The complementary electrochromic device, where the optical transmittance changes upon the flow of cations back and forth between anodic and cathodic electrodes, operates in a rocking-chair fashion if it can inherently self-discharge. Herein, the first demonstration of a dual-mode electrochromic platform having self-coloring and self-bleaching characteristics is reported, which is realized by sandwiching zinc metal within a newly-designed Prussian blue (PB)-WO₃ rocking-chair type electrochromic device. It is demonstrated that the redox potential differences between the zinc metal and the WO₃/PB electrodes endow the self-color-switching of these electrodes. By employing a hybrid electrolyte of Zn²⁺/K⁺, it is further shown that the colored PB-WO₃ rocking-chair device is capable of spontaneously bleaching when the anodic and cathodic electrodes are coupled. This dual-mode light-control strategy enables the electrochromic devices to exhibit four distinct optical states with the highest optical contrast of 72.6% and fast switching times (<5 s for the bleaching/coloration processes). Furthermore, the built-in voltage of the dual-mode electrochromic devices not only promotes energy efficiency, but also augments the bistability of the devices. It is envisioned that the broad implication of the present platform is in the development of self-powered smart windows, colorful displays, optoelectronic switches, and optical sensors.     

Black-to-transmissive electrochromism of azulene-based donor–acceptor copolymers complemented by poly(4-styrene sulfonic acid)-doped poly(3,4-ethylenedioxythiophene)

A series of azulene–carbazole–2,1,3-benzothiadiazole (BTD) conjugated terpolymers were synthesized and their electrochemical and electrochromic properties were studied. The terpolymer containing a small amount of BTD units exhibits significantly higher electrochromic contrast and faster switching speed than azulene–carbazole alternating copolymer under low potentials because the BTD units act as electron acceptors, facilitating electron removal from azulene and carbazole units (electron donors) upon oxidation and hence leading to a lower oxidation potential. A complementary electrochromic device (ECD) was fabricated using the terpolymer as the anodically coloring layer and poly(4-styrene sulfonic acid)-doped poly(3,4-ethylenedioxythiophene) (PEDOT:PSS) as the cathodically coloring layer. The ECD exhibits black-to-transmissive electrochromism as the absorption bands of the two polymers are complementary to each other in covering the whole visible region and they can be switched simultaneously under relatively low potentials.     

Effects of Pre‐reducing Sb‐Doped SnO2 Electrodes in Viologen‐Anchored TiO2 Nanostructure‐Based Electrochromic Devices

In this paper, we investigate the effects of pre‐reducing Sb‐doped SnO₂ (ATO) electrodes in viologen‐anchored TiO₂ (VTO) nanostructure–based electrochromic devices. We find that by pre‐reducing an ATO electrode, the operating voltage of a VTO nanostructure–based electrochromic device can be lowered; consequently, such a device can be operated more stably with less hysteresis. Further, we find that a pre‐reduction of the ATO electrode does not affect the coloration efficiency of such a device. The aforementioned effects of a pre‐reduction are attributed to the fact that a pre‐reduced ATO electrode is more compatible with a VTO nanostructure–based electrochromic device than a non‐pre‐reduced ATO electrode, because of the initial oxidized state of the other electrode of the device, that is, a VTO nanostructure–based electrode. The oxidation state of a pre‐reduced ATO electrode plays a very important role in the operation of a VTO nanostructure–based electrochromic device because it strongly influences charge movement during electrochromic switching.