Slow Gold Adatom Diffusion on Graphene: Effect of Silicon Dioxide and Hexagonal Boron Nitride Substrates

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• 作者：Li Liu ; Zheyuan Chen ; Lei Wang ; Elena Polyakova (Stolyarova) ; Takashi Taniguchi ; Kenji Watanabe ; James Hone ; George W. Flynn ; Louis E. Brus
• 刊名：The Journal of Physical Chemistry B
• 出版年：2013
• 出版时间：April 25, 2013
• 年：2013
• 卷：117
• 期：16
• 页码：4305-4312
• 全文大小：530K
• 年卷期：v.117,no.16(April 25, 2013)
• ISSN：1520-5207

文摘

We examine the nucleation kinetics of Au clusters on graphene and explore the relationship with layer number and underlying supporting substrate of graphene. Using the mean field theory of diffusion-limited aggregation, morphology patterns are semiquantitatively analyzed to obtain Au adatom effective diffusion constants and activation energies. Under specified assumptions, the Au adatom diffusion constant for single-layer graphene supported on SiO₂ is 50 times smaller than that for hexagonal boron nitride (h-BN)-supported graphene and on the order of 800 times smaller than that for multilayer graphite. Bilayer graphene on SiO₂ shows a Au adatom diffusion constant similar to single-layer graphene on h-BN. Scanning probe data show that single-layer graphene is far flatter on h-BN than on SiO₂. Two factors are proposed as contributing to the observed lower diffusion constants on single-layer graphene: local surface roughness and homogeneous loss of dispersion/van der Waals electronic stability in multilayers. Graphene Raman spectroscopy shows little charge transfer between Au nanoparticles and graphene.