[表面科学论坛(90)] Metal on and under graphene: Growth morphology and effects of intercalation
||Dr. Cai-Zhuang Wang
Ames Laboratory - US DOE and Department of Physics and Astronomy, Iowa State University
Understanding metal nucleation and growth on graphene is essential for optimizing electrical contacts and to grow high density islands for magnetic and catalytic applications. Using scanning tunneling microscopy, we investigated the growth morphology of various metals on graphene on Si-terminated SiC substrate. We have also carried out first-principles calculations to establish the correlation between the adatom adsorption properties and the growth morphology. We show that the growth morphology is related to the ratio of the metal adsorption energy to its bulk cohesive energy (Ea/Ec) and the diffusion barrier (DE) of the metal adatom on graphene. We also show that most of the metal nanostructures on graphene are thermally stable against coarsening. We have also investigated the effects of metal intercalation on the properties of graphene. We show that metal intercalation can substantially modify the graphene band structure. Partial metal intercalation can also induce an alternating electric field across the graphene surface due to the spatial variations in electron doping. This alternating field can change normal stochastic adatom diffusion to biased diffusion, leading to selective mass transport and consequent nucleation.
Work supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences, Materials Science and Engineering Division. The research was performed at Ames Laboratory, which is operated for the U.S. DOE by Iowa State University under contract # DE-AC02-07CH11358.
Dr. Cai-Zhuang Wang is a senior scientist at Ames Laboratory, US Department of Energy, and an adjunct professor at Department of Physics and Astronomy, Iowa State University. He received B.S. in physics from University of Science and Technology of China and Ph.D in Condensed Matter Physics from International School for Advanced Studies (SISSA), Trieste, Italy. He is a fellow of American Physical Society. His research interest is in the areas of condensed matter theory and computational materials Science. He has published more than 350 papers with h-index 48.
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