Decoupling of CVD graphene by controlled oxidation of recrystallized Cu
Decoupling of CVD graphene by controlled oxidation of recrystallized Cu
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DOI：
10.1039/c2ra01281b
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发表时间：
2012-01-01
期刊：
影响因子：
3.9
通讯作者：
Juang, Zhen-Yu
中科院分区：
文献类型：
--
作者：
Lu, Ang-Yu;Wei, Sung-Yen;Juang, Zhen-Yu
化学气相沉积（CVD）法制备大面积石墨烯具有广阔的应用前景；然而，石墨烯与衬底之间的相互作用仍然没有得到很好的理解。在本报告中，我们结合了两种非破坏性表征技术，即电子背散射衍射（EBSD）和拉曼映射，在不去除石墨烯的情况下局部探测石墨烯和铜晶格之间的界面。我们得出结论，石墨烯层下Cu晶粒的晶体结构受两个相互竞争的过程控制：(1)石墨烯诱导Cu表面重构有利于Cu（100）取向的形成；(2)大块Cu的再结晶有利于Cu（111）取向的形成。无论是重建还是再结晶，底层的Cu晶粒都会对石墨烯晶格产生较大的流体静力压缩。有趣的是，这种强相互作用可以通过允许插入一层薄薄的氧化亚铜界面层来解耦。Cu2O层机械和化学性质较弱；因此，石墨烯薄膜可以分离并转移到任意衬底上，并且Cu衬底可以重复用于石墨烯生长。
Large-area graphene grown by chemical vapour deposition (CVD) is promising for applications; however, the interaction between graphene and the substrate is still not well understood. In this report, we use a combination of two non-destructive characterization techniques, i. e., electron backscatter diffraction (EBSD) and Raman mapping to locally probe the interface between graphene and copper lattices without removing graphene. We conclude that the crystal structure of the Cu grains under graphene layers is governed by two competing processes: (1) graphene induced Cu surface reconstruction favoring the formation of Cu(100) orientation, and (2) recrystallization from bulk Cu favoring Cu(111) formation. The underlying Cu grains, regardless of reconstruction or recrystallization, induce a large hydrostatic compression to the graphene lattice. Interestingly, the strong interaction could be decoupled by allowing the intercalation of a thin cuprous oxide interfacial-layer. The Cu2O layer is mechanically and chemically weak; hence, graphene films can be detached and transferred to arbitrary substrates and the Cu substrates could be re-used for graphene growth.