Nucleation and Growth of Epitaxial Graphene Formed by Physical Vapor Deposition

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Technical: This project is on the growth and properties of monolayer graphene and graphene based heterostructures formed by solid-source molecular beam epitaxy (MBE). The well-controlled carbon deposition rates made possible by MBE enable the growth of films under a wide range of kinetic conditions while removing effects related to carbon precursor chemistry, which exist naturally in the commonly used chemical vapor deposition processes. The research is inspired by recent studies of graphene grown on copper foils, which show graphene island nucleation as the ultimate bottleneck to achieving pristine graphene in this system. The project, building on these results, investigates the conditions that lead to controlled graphene nucleation and probes the critical interactions between graphene edge atoms and substrate adatoms, which play a key role in island evolution. Experiments of graphene growth on different substrates by low-energy electron microscopy is expected to provide fundamental insight into the roles of substrate texture, lattice mismatch, substrate stepflow, and interfacial interactions. In addition, MBE will be used to form graphene-dielectric bilayers under ultrahigh vacuum conditions, which will be studied further via electrical, structural and optical measurements.Nontechnical: The project addresses basic research issues in a topical area of materials science with high technological relevance. The application of molecular beam epitaxy to graphene growth brings the extensive capabilities of this advanced deposition technique into the fold of graphene science and technology. If the project is successful, new functionalities and enhanced properties can emerge through the formation of pristine interfaces between graphene and other materials. An education plan is integrated with the research and brings together emerging scholars from across different levels of higher education, community college to graduate school, for the study of graphene. Outreach project activities center on the integration of original research concepts into summer experiences for undergraduates and community college students from traditionally underrepresented groups in science and engineering. Summer investigations on graphene will serve as test beds for lab instructional modules that will be implemented in a senior-level, capstone laboratory course.