Scaling Properties of Charge Transport in Polycrystalline Graphene

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• 作者：Dinh Van Tuan ; Jani Kotakoski ; Thibaud Louvet ; Frank Ortmann ; Jannik C. Meyer ; Stephan Roche
• 刊名：Nano Letters
• 出版年：2013
• 出版时间：April 10, 2013
• 年：2013
• 卷：13
• 期：4
• 页码：1730-1735
• 全文大小：406K
• 年卷期：v.13,no.4(April 10, 2013)
• ISSN：1530-6992

文摘

Polycrystalline graphene is a patchwork of coalescing graphene grains of varying lattice orientations and size, resulting from the chemical vapor deposition (CVD) growth at random nucleation sites on metallic substrates. The morphology of grain boundaries has become an important topic given its fundamental role in limiting the mobility of charge carriers in polycrystalline graphene, as compared to mechanically exfoliated samples. Here we report new insights to the current understanding of charge transport in polycrystalline geometries. We created realistic models of large CVD-grown graphene samples and then computed the corresponding charge carrier mobilities as a function of the average grain size and the coalescence quality between the grains. Our results reveal a remarkably simple scaling law for the mean free path and conductivity, correlated to atomic-scale charge density fluctuations along grain boundaries.

Keywords:

Polycrystalline graphene; grain boundaries; charge transport; mobility