新型MoO3电致变色薄膜的制备及性能研究

	新型MoO3电致变色薄膜的制备及性能研究
其他题名	Preparation and Properties of Novel MoO3 Electrochromic Films
	刘岩
学位类型	硕士
导师	刘星元
	2015-11
学位授予单位	中国科学院大学
学位专业	凝聚态物理
关键词	电致变色透明导电膜柔性介质/金属/介质 Moo3/ag/moo3 无ito 稳定性
摘要	电致变色器件（Electrochromic devices, ECDs）在智能窗、显示、军事等领域具有广阔的应用前景。ECDs的基本结构包括：透明导电层I、电致变色层、电解质层、离子存储层以及透明导电层II。目前ECDs中的透明导电层主要采用In2O3:Sn (ITO) 薄膜，ITO电阻低、透过率高，但铟元素为稀有元素价格昂贵，提高了ECDs成本。并且ITO柔韧性差，不耐弯折，限制了柔性ECDs的开发和应用。介质/金属/介质（Dielectric-metal-dielectric，简称DMD）结构薄膜由于其透过率高、电阻率低、柔韧性好、生产成本低等优点，是一种较为理想的透明导电薄膜。我们前期的研究发现，采用具有电致变色功能的材料为介质层，可以构筑兼具透明导电和电致变色双重功能的DMD薄膜，实现高性能的刚性ECDs。鉴于柔性ECDs研究的重要意义以及存在的问题，本文在前期工作的基础上，以获得高性能柔性ECDs为目标，采用经典电致变色材料MoO3作为介质层，Ag作为金属层，构建集电致变色和透明导电功能为一体的MoO3/Ag/ MoO3（MAM）薄膜。通过系统研究薄膜组成、结构和性质的关系，获得响应速度快、对比度高、着色效率高、稳定性好的刚性和柔性ECDs。主要研究内容如下： 1. 利用电子束蒸镀技术，在玻璃衬底上制备刚性MAM薄膜。采用理论模拟和实验验证相结合的方法，优化薄膜厚度，获得导电性优异和透过率良好的MAM（30/11/50 nm）薄膜，其面电阻仅为9.3 Ω □-1，可见光（400~800 nm）平均透过率为59.4%。同时，MAM表现出优异的电致变色性质。与ITO电极上的MoO3（50 nm）薄膜相比，MAM的着色效率更高（40.5 vs. 23.6 cm2 C-1）、对比度更大（30.9 vs. 20.4%，528 nm），且循环稳定性较好。为进一步获得高性能柔性ECDs奠定基础。 2. 在柔性PET（Polythylene terephthalate）衬底上制备MAM薄膜，该薄膜具有较好的耐弯折性能和循环稳定性。MAM薄膜经2000次弯折，电阻变化较小（从12.5 Ω □-1增大到26.7 Ω □-1），而PET/ITO/MoO3（50 nm）的电阻显著增加（从30.5 Ω □-1增大到1134 Ω □-1）。此外，PET/MAM薄膜的电致变色性能尤其是稳定性也明显优于PET/ITO/MoO3, 柔性MAM的着色效率达到34.9 cm2 C-1，对比度为27.7 %，循环稳定性大于200次，耐弯折性能大于2000次。以上研究，为制备高性能柔性ECDs提供了新思路。
其他摘要	Electrochromic devices (ECDs) can be wildly used in smart windows, displays, militaries and other fields. The basic structure of ECDs have five layers, including transparent conducting layer I, electrochromic layer, electrolyte layer, ion storage layer, and transparent conducting layer II. At present, Indium tin oxide (ITO) film is the most commonly used transparent conducting layer because of its low resistance and high transmittance. But the rare of Indium element cause that ITO film is expensive and high-cost. On the other hand, its brittleness limits the development and applications of flexible ECDs. Dielectric-metal-dielectric (DMD) structure film is considered a more ideal transparent conducting layer, which exhibits high transmittance, low resistance, good flexibility and low cost. Our previous study found that by employing high performance electrochromic material as a dielectric layer, we can integrate the transparent conducting layer and electrochromic layer bi-functionality in one DMD film, which can simplify achieve the high performance of the rigid ECDs. In view of the important significances and challenges of flexible ECDs and in order to obtain high performance flexible ECDs, based on the previous work, we choose the classic MoO3 as the dielectric layer and Ag as the metal layer, and set up a MoO3/Ag/MoO3 (MAM) thin film which combine the function of the transparent conducting layer and the electrochromic layer. Through systematic study the relationship between the composition, structure and properties of MAM film, we could obtain high-performance flexible and rigid ECDs with rapid response time, high optical contrast, high efficiency and good stability. The main research contents are as follows: 1. We prepared MAM films on glass substrates by electron beam evaporation technique. By using a method of the combination of the numerical simulationand the experimental validation and optimizing the film thickness, we obtained high performance MAM (30/11/50 nm) film, which reveals excellent conductivity and high transmittance. Its surface resistance is only 9.3 Ω □-1 and average transmission in visible light range (400 ~ 800 nm) is 59.4%. Additionally, the MAM film shows excellent electrochromic properties. Compared with MoO3 （50 nm） film on ITO transparent conductor layer, MAM (30/11/50 nm) films have higher electrochromic colored efficiency (40.5 vs. 23.6 cm2 C–1), higher optical contrast (30.9 vs. 20.4%，528 nm) and better cyclic stability. These results laid the foundation down for further high performance flexible ECDs study. 2. We further prepared MAM films on flexible polythylene terephthalate (PET) substrates by electron beam evaporation technique. The optimized flexible MAM film has achieved excellent electrochemical and mechanical durability. After 2000 times bending test, the resistance of the flexible MAM (30/11/50 nm) film changed slightly from 12.5 Ω □-1 to 26.7 Ω □-1. In contrast, the resistance of the PET/ITO/MoO3（50 nm）significantly increased from 30.5 Ω □-1 increases to 1134 Ω □-1. In addition, the electrochromic property of the flexible MAM film is also significantly better than that of PET/ITO/MoO3 film. The electrochromic colored efficiency of the flexible MAM is 34.9 cm2 C–1, the optical contrast is 27.7%, the cyclic stability is more than 200 times, and the bending property is more than 2000 times. All researches above would provide a new approach for the preparation of high performance flexible ECDs.
语种	中文
文献类型	学位论文
条目标识符	http://ir.ciomp.ac.cn/handle/181722/49228
专题	中科院长春光机所知识产出
推荐引用方式 GB/T 7714	刘岩. 新型MoO3电致变色薄膜的制备及性能研究[D]. 中国科学院大学,2015.

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