银纳米棒桥联石墨烯基透明导电薄膜的制备及性能研究

Due to its unique two-dimensional structure and exceptional physical and chemical properties, graphene is widely considered to be an ideal material for fabricating high-performance transparent conductive films, and thus expected to replace resource-scarce and brittle indium tin oxide and show great potential in many fields such as flexible display devices, organic solar cells, and smart windows. This project will target potential utilization of nanoscale assembly techniques in transparent conductive films, propose to assemble a kind of structure-tunable periphery-functionalized graphene sheets with silver nanorods at the molecular level or nanoscale, process them into silver nanorod-bridged graphene-based transparent conductive films, and study the opto-electrical properties of the thus-fabricated films. The project will elaborately tailor the structure of periphery-functionalized graphene with silver nanorods, systematically investigate the effects of the interface number of graphene sheets and the interface type between graphene sheets within these films on their opto-electrical properties, and establish the structure-property relationships of these transparent conductive films. Based on optimizations on components and structures of silver nanorod-bridged graphene-based transparent conductive films, the project will demonstrate a prototype of transparent conductive film simultaneously with high visible light transparency and high electrical conductivity, providing a substantial scientific platform for applied study of graphene-based transparent conductive films.

由于其独特的二维结构和优异的物理、化学特性，石墨烯被认为是制备高性能透明导电薄膜的理想材料，有望取代资源缺乏、脆性的氧化铟锡，在柔性显示、有机太阳能电池、智能窗等领域表现出巨大的应用潜力。本项目探索纳米组装技术在透明导电薄膜领域的应用，从分子水平和纳米尺度上合成一类结构可调控的银纳米棒边缘功能化石墨烯材料，制备银纳米棒桥联石墨烯基透明导电薄膜，并研究制得的薄膜的透光、导电性能；通过对银纳米棒边缘功能化石墨烯及其薄膜结构的调控，系统深入地研究和探讨银纳米棒桥联石墨烯基透明导电薄膜中石墨烯片层的搭接数量、石墨烯片层间的搭接方式对其透光、导电性能的影响，建立其结构与性能间的相关关系；通过对材料及其薄膜结构的优化，开发一种新型的兼具优异透光性和导电性的透明导电薄膜原型，为石墨烯基透明导电薄膜的实用化研究提供实验依据和奠定科学基础。

石墨烯结构及特性在宏观应用中的保持一直是石墨烯研究领域的难点。我们在制备银纳米棒桥联石墨烯基透明导电薄膜的过程中，发现石墨烯的形态结构是决定其性能的关键因素。鉴于此，对本项目研究内容进行了适当调整，重点开展了石墨烯的控制制备和组装及其性能研究。本项目建立了利用金属锡、氯化亚锡还原氧化石墨烯薄膜的方法，其具有条件温和、效率高及与卷对卷涂膜工艺相兼容等优点，所得薄膜表现出高的透光性和导电性。提出并发展了一种可规模化、无损转移石墨烯的可逆功能化策略，其主要包括羟基功能化石墨烯的可控制备及氢碘酸还原，基于该策略制得的石墨烯薄膜表现出明显提高的透光性和导电性，基于羟基功能化石墨烯的锂离子电池负极材料表现出优异的储锂性能；发展了一种边缘选择性功能化石墨烯的化学溶液法，制备了高质量的边缘羧基化石墨烯。此外，研究了石墨烯与硅纳米材料的自组装行为，可控组装了均匀负载硅量子点的石墨烯和含硅纳米粒子的模板碳桥联取向石墨烯宏观体，其具有显著提高的导电性及储锂性能。上述研究不仅较好解决了石墨烯的难溶解性，还在一定程度上确保了石墨烯的结构、界面以及特性在宏观材料及器件中的保持，为石墨烯的控制制备及在透明导电薄膜、锂离子电池等领域的应用奠定了基础。