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.
