可见-近红外分区可控全固态柔性电致变色器件的构筑与性能研究

Electrochromic materials refer to a kind of compounds that can reversibly change light transmission properties in response to voltage and thus allow control over the amount of light transmitted, heat passing through and color appearance. On the basis of such interesting phenomenon, electrochromic materials have been widely used for nonradiative low-energy display device, graphic technology, sensors, dimming rearview mirror and infrared camouflage. In this proposal, we plan to fabricate the tungsten suboxide/polyoxometalates based all-solid-state electrochromic flexible device that can selectively control the transmittance of visible and near-infrared light independently. As a result, such a novel electrochromic device will cater to different needs and create multifunction-in-one. As compared with already reported ones, the electrochromic device of this work possesses several advantages: (1) high controllability: selectively control the transmittance of visible and near-infrared light in independently and stepwise manner: (2) promoted electrochromic properties: the nanostructures used in this study combined the merits of fast-response of amorphous electrochromic materials and high-stability of electrochromic crystalline: (3) high availability: all-solid-state and flexible device is suitable for many applications.

电致变色是指材料在改变外加电场作用下实现材料光学属性发生稳定、可逆变化的现象，基于此类特性电致变色材料被广泛应用于非辐射低能耗显示器，电子束印刷技术及传感器，汽车防眩目后视镜和武器装备红外隐身和伪装。本项目计划开发基于纳米钨低价氧化物和多金属氧簇复合型电致变色薄膜，用于构筑能够实现对可见光和近红外线分区、分步可控全固态柔性电致变色器件，更好地发挥其灵动多变的优势，实现一体多能的新型电致变色器件。与已有报道的电致变色器件相比，本项目的创新点和优势在于：（1）高度可控性：可以分光区逐步地、独立地电致变色控制可见光和近红外的透过率；（2）优异的电致变色性能：纳米结构为主体的多酸和钨低价氧化物体系，融合了晶态物质电致变色性能稳定和非晶态电致变色响应速度快的双重优点；（3）广阔的应用领域：全固态柔性电致变色器件可以有效的避免液态变色器件中电解液易泄漏、爆炸危险，可以被任意折叠和弯曲，适用面广。

开发可见-近红外光分区可控电致变色把薄膜具有重大的研究意义和应用前景，如可作为可调控光照的帷幔，非辐射低能耗显示器，活性光能滤波器，电子束印刷技术及传感器，汽车防眩目后视镜等诸多领域。本项目以还原态钨物种作为近红外光光学材料分别与多金属氧酸盐和相变液晶材料两种可见光调控组分构筑了两种可见-近红外光分区可控薄膜。本项目首先将W18O49与多金属氧酸盐通过经典层层自组装技术构筑与同一薄膜，并且通过二者电致变色窗口上的电位差分步的调控可见光与近红外光的屏蔽效果。之后的研究还将CsXWO3与相变液晶材料通过卷对卷的方式分散于可大规模制备的高分子薄膜中，该固态薄膜可以通过热、电、近红外光三重刺激调控液晶相变与可见光透过。此外，薄膜中CsXWO3可控制近红外光的透过以及起到光热效果诱发液晶相变。综合以上，本项目获得了以上两种薄膜均满足了光学分区可控的要求。