摘 要

随着科学技术的发展，透明导电薄膜在当今社会的光电子器件等领域扮演着愈发重要的角色。拥有高导电性和透过率的传统材料ITO作为透明导电薄膜已成功地运用于光电子器件中长达五十多年，但由于其自身的各种因素使其发展受到了极大的限制。因此，研究新型的透明导电薄膜材料显得尤为重要。在可替代ITO的材料中，石墨烯和微米银网络被认为是非常有前景下一代透明电极材料。

而随着显示技术与光通讯技术的蓬勃发展，对电子器件材料的制备，提出了高效低能、工艺简便可重复性强、绿色清洁等要求。喷墨打印的印刷方法作为一种新型非接触式印刷技术，具有材料利用率高、低成本、适用于柔性和刚性基底等优点。将喷墨打印法制备的微米银网络与石墨烯相结合，可大幅提高透明导电薄膜的光电性能和稳定性，纳米银墨水和石墨烯的低热处理温度使基底的柔性化发展成为可能。喷墨打印技术中对印刷图案的精细化控制，更是使透明电极材料达到了节省成本、提高效率、实现多样化应用的效果。

本实验主要研究了基于喷墨打印法制备具有优异导电性能和透光性能的微米银网络的过程，比较了基于喷墨打印法的各种打印参数，诸如打印图案、打印基底温度、打印基底不同而制备的微米银网络的光电性能和形貌的差异。成功运用喷墨打印的制备方法，制备具有良好导电性和透光性的微米银网络薄膜，并运用石墨烯和纳米银线改善其光电性能和形貌，增强其在太阳能电池器件领域的应用前景。

研究结果表明，运用喷墨打印法，可通过在60℃的钠钙玻璃上打印8遍20线2cm²网格图案以获得具有最佳的透明导电性能的薄膜，微米银网络能达到1.1Ω/sq的方阻和550nm波长下77.6%的透过率。在柔性基底PET上，虽打印效果和光电性能都有所下降，但仍能获得方阻低至2.2Ω/sq和在550nm波长下透过率高达76.5%的打印6遍的高透高导微米银网络薄膜。为获得连续平整的可应用于太阳能电池器件的高透高导薄膜，将石墨烯和纳米银线分别用刮涂法和喷涂法与喷墨打印的微米银网络相复合。运用刮涂法制备的石墨烯（纳米银线）复合微米银网络，可以在有限的降低微米银网络的透光性的基础上极大的提升银网络的导电性能，与此同时，在一定程度上也可填充微米银网络结果所带来的台阶，使其有利于在太阳能电池器件上的应用。

关键词：微米银网络；喷墨打印；透明导电薄膜；石墨烯

Abstract

With the development of technology, the role which transparent conductive films playing in the fields of optoelectronics has been increasingly important. The traditional material for transparent conductive films, indium tin oxide (ITO), has been applied to optoelectronic devices successfully for more than fifty years thanks to its good performance in conductivity and transmittance. However, its instinct properties limit the development of ITO. Hence, it is of vital importance to put effort into the research of new materials for transparent conductive films. Among the alternatives for ITO, graphene and micro-silver networks are considered as the next-generational transparent conductive materials with great expectation.

With the prosperous development of display technique and photo-communication technology, there has been raising requirements such as high efficiency, low energy consumption, simple fabrication process, environmental protecting etc. in the preparation of electronic materials. Ink-jet printing is a novel contactless printing technique with high utilization of materials, low cost and good application in flexible and rigid substrates. By combining the graphene with micro-silver networks prepared by ink-jet printing, the photo and electronic properties and stability of the as-prepared transparent conductive films can be greatly improved. Also, the low heating temperature for nano-silver inks and graphene enables the substrate to be flexible. The precise digital control of printing patterns in ink-jet printing contributes to the lower cost, higher efficiency and diversity in application of the transparent conductive films.

This paper mainly studies the process of high conductivity and high transparency micro-silver networks based on an ink-jet printing method. It compares the different printing parameters such as printing pattern, substrate temperature and substrate in ink-jet printing and compare the differences in optical and electronic properties and differences in appearances of micro-silver networks. Fine micro-silver networks with extraordinary optical and electronic properties are successfully prepared by an ink-jet printing method and the prepared networks are combined with graphene and silver nanowires to improve their optical and electronic performance and appearances and to improve the potential of future application in fields of solar cells.

The study shows that the properties of transparent conductive films are optimized when print the 20-lines 2cm² pattern 8 times on a glass substrate heated to 60℃. The printed micro-silver network can attain a sheet resistance down to 1.1Ω/sq and a transmittance up to 77.6% under the wavelength of 550nm. In the case of flexible substrate (i.e. PET), although the printing performance and optical and electronic properties are decrease to some point, a transparent conductive micro-silver film, of which the sheet resistance is down to 2.2Ω/sq and the transmittance is up to 76.5% under the wavelength of 550nm, can still be obtained by ink-jet printing the 20-lines 2cm² pattern 6 times on a PET substrate heated to 60℃. In order to obtain uniform and smooth transparent conductive films that can be applied to devices such as solar cells, graphene and silver nanowires are added to the ink-jet printed micro-silver networks by means of blade coating and spray coating. The graphene/micro-silver network composite films prepared by blade coating can enhance the optical and electronic properties of the transparent conductive films significantly and in the mean time fill in the blanks brought by the ink-jet printed micro-silver networks, which benefits them a lot for their application in fields of devices such as solar cells.

Key Words: Micro-silver networks; Ink-jet printing; Transparent conductive films; Graphene

目 录

摘 要 I

Abstract II

第1章 绪论 1

第2章 文献综述 3

2.1 印刷电子技术 3

2.1.1 印刷电子技术概述 3

2.1.2 喷墨打印技术 5

2.2 喷墨打印墨水 7

2.2.1 喷墨打印墨水的物理性质 7

2.2.2 纳米银墨水 7

2.3 透明导电薄膜 8

2.3.1 透明导电薄膜概述 9

2.3.2 石墨烯复合银高透高导薄膜 9

第3章 实验方法及研究方法 11

3.1 实验方案 11

3.1.1 微米银网络的制备 11

3.1.2 微米银网络复合石墨烯薄膜的制备 11

3.1.3 主要创新点 11

3.2 研究方法 11

3.2.1 实验试剂 11

3.2.2 喷墨打印机 12

3.3 表征方法 13

3.3.1 光学显微镜 13

3.3.2 紫外-可见-近红外分光光度计 13

3.3.3 台阶仪 13

3.3.4 表面电阻的表征 14

3.3.5 接触角测量仪 14

第4章 微米银网络的制备与表征 15

4.1 JET-605C墨水的初步探索 15

4.2 喷墨打印微米银网络的初步探索 16

4.3 微米银网络的喷墨打印制备与表征 20