SBIR Phase I: Development of Large-Area Crystal-Aligned Substrates for Epitaxial Graphene

这个小企业创新研究（SBIR）第一阶段项目解决了对石墨烯薄膜衬底的需求。石墨烯是一种独特的二维材料，被称为？奇迹材料吗?由于其非凡的结构和电子性能，可用于许多应用。然而，石墨烯是一种相对较新的材料，因此仍然不能大面积地可重复制造。通过在碳化硅上的表面分解和在铜等催化金属上的化学气相沉积，在单晶上合成了高度完美的外延石墨烯薄膜。然而呢?外延生长吗?石墨烯原子在衬底上的位置受到单晶衬底要求的限制。石墨烯沉积在标准多晶材料上，由于衬底中的晶粒不匹配，导致其电子性能不理想。在这个项目中，我们利用离子束辅助沉积技术在玻璃和金属箔等各种表面上制作单晶涂层。我们探索这些人工排列的薄膜，以生产大面积的基底沉积外延石墨烯。这种衬底将使人们能够在许多不同的表面上沉积高性能的外延石墨烯，而不需要刚性的单晶衬底。该项目更广泛的影响/商业潜力是提供一种大面积制造高质量石墨烯薄膜的技术。石墨烯具有很高的导电性、光学透明性和机械坚固性等特性，使其成为光伏、显示器和其他光电器件中透明电极的优秀候选者。然而，仍然需要一种技术来在各种不同的表面上提供大面积的高性能石墨烯。通过提供一种可扩展的晶体排列方法薄膜沉积，离子束薄膜对准技术可以反过来使大面积外延石墨烯薄膜的生产。这些石墨烯薄膜的质量应该接近小单晶片的质量。这种晶体排列模板的使用已经被证明是外延超导薄膜，用于制造千米长的高温超导体线。

This Small Business Innovation Research (SBIR) Phase I project addresses the need for substrates for graphene films. Graphene is a unique two-dimensional material that has been called the ?miracle material? because of its extraordinary structural and electronic properties that can be used in many applications. However, graphene is a relatively new material and as such is still not reproducibly fabricated in large areas. Highly perfect epitaxial graphene films have been synthesized on single crystals via surface decomposition on silicon carbide and by chemical vapor deposition on catalytic metals such as copper. However ?epitaxial growth? where graphene atoms are in registry with the substrate is limited by the single-crystal substrate requirement. Electronic properties of graphene deposited on standard polycrystalline materials are not optimal due to grain mismatch in the substrate. In this project we utilize ion-beam assisted deposition technology to make single-crystal like coatings on a variety of surfaces such as glass and metal foils. We explore these artificially aligned films to produce large area substrates for deposition of epitaxial graphene. Such substrates would enable one to deposit high-performance epitaxial graphene on many different surfaces without the need for rigid single-crystal substrates.The broader impact/commercial potential of this project is to provide a technology for large-area fabrication of high-quality graphene films. Graphene offers a singular combination of properties such as very high conductivity, optical transparency, and mechanical robustness, making it an excellent candidate for transparent electrodes in photovoltaics, displays, and other optoelectronic devices. However, what is still needed is a technology for providing large-area high-performance graphene on a variety of different surfaces. By providing a scalable method of ?crystal-aligned? film deposition, the ion-beam film aligning technology can in turn enable large-area epitaxial graphene films to be produced. These graphene films should approach the quality of those made on small single-crystal wafers. Use of such crystal-aligned templates has already been proven for epitaxial superconducting films that are used to manufacture high temperature superconductor wire in kilometer lengths.