绝缘基底上高品质石墨烯的可控直接制备及其基础应用研究

Graphene has by far stimulated enormous research interest due to its excellent properties and vast application prospects. In this regard, the graphene synthesis determines the future of such a unique material, where controllable and scalable synthesis of graphene with large-area and high-quality is critical for the realization of graphene based applications. To date, high-quality graphene can be catalytically grown on metallic substrate by virtue of traditional chemical vapor deposition (CVD) method. However, the as-produced graphene needs to be transferred onto an insulating substrate for further device construction and practical applications. The inevitable transfer process from metal onto dielectric substrates is nevertheless tedious and cost-ineffective, which might also introduce wrinkles, breakages, defects, and metallic contaminations/residues on the graphene samples. Based on these, herein we propose direct CVD synthetic strategies to fabricate transfer-free, high-quality graphene on conventional and novel insulating substrates in a controllable manner. This research proposal encompasses three parts: 1) To develop fast, scalable and low-temperature synthesis technique as well as investigate the direct growth of graphene on flexible insulating substrates; 2) To achieve the direct growth of graphene/hexagonal boron nitride heterostructures and explore its device performance; 3) To establish the standard synthetic technique for the direct growth of three-dimensional graphene, which targets the applications in energy storage and conversions.

石墨烯因其优异的性质和广阔的应用前景成为当今的研究热点。而石墨烯的未来取决于其制备，即能否规模化可控合成高品质的石墨烯是其应用能否真正实现的关键。借助传统的化学气相沉积法在金属基底上催化生长的石墨烯，需借助转移到绝缘基底上才能进行后续的器件构筑。然而，转移过程总是不可避免地带来石墨烯的破损、褶皱，引入金属、溶剂残留污染，以及存在工艺复杂、成本高等问题，很大程度上制约着石墨烯基器件的设计和性能。本项目拟采用直接化学气相沉积技术在常规及新型绝缘基底上原位可控合成石墨烯。通过寻找高效易裂解的碳前驱体、选择合适的加热方式等，发展高品质石墨烯的低温快速生长方法、在柔性基底上的直接制备技术及放量制备工艺；从直接制备的氮化硼薄膜入手，实现石墨烯/氮化硼层间异质结材料的可控合成，探索其在微/纳电子器件中的应用；通过调控基底种类，设计反应步骤等，建立三维石墨烯原位制备的标准化工艺，并将其应用于能源领域。

直接在绝缘基底上制备石墨烯是当前石墨烯基础研究领域非常具有开发和应用前景的体系。我们通过此项目实施，系统展示了运用化学气相沉积技术在绝缘基底上可控直接制备石墨烯，对石墨烯材料的商业化应用起到了推动作用。所使用的基底包括柔性玻璃、三维氧化物粉体以及玻璃纤维隔膜等。通过寻找高效易裂解的碳前驱体、选择合适的加热方式等，发展可控品质石墨烯在绝缘基底上的直接制备技术；通过调控基底种类，设计反应步骤等，实现石墨烯三维结构的原位合成，将其应用于能源领域。具体工作包括：1）采用泡沫铜辅助的化学气相沉积技术实现了5英寸具有大面积宏观均匀性的柔性石墨烯玻璃的可控直接制备。2）采用等离子体辅助的化学气相沉积方法在氧化物粉体上直接生长了少层的石墨烯包覆层，并实现了具有高功率密度-高能量密度钠离子混合电容器的成功组装；3）实现了石墨烯在商用玻璃纤维隔膜上的直接生长，此种新型烯碳隔膜在水系锌离子电池中发挥了优异的性能。