Graphene oxidation: Thickness-dependent etching and strong chemical doping
Graphene oxidation: Thickness-dependent etching and strong chemical doping
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DOI：
10.1021/nl0808684
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发表时间：
2008-07-01
期刊：
影响因子：
10.8
通讯作者：
Flynn, George W.
中科院分区：
文献类型：
--
作者：
Liu, Li;Ryu, Sunmin;Flynn, George W.
图案化石墨烯在未来分子级集成电子学中显示出巨大的应用潜力。对于每个原子都位于表面的单层材料来说，环境影响是一个关键问题。特别有趣的是分子氧与芳香族分子表现出的各种丰富的化学相互作用。我们发现 O-2 蚀刻动力学随样品中石墨烯层数的变化而强烈变化。三层厚的样品显示出与块状天然石墨类似的蚀刻。与在点缺陷处成核的天然石墨相比，单层石墨烯反应更快，并显示出随机蚀刻坑。此外，基面氧物质对石墨烯进行强烈空穴掺杂，费米能级位移约为 0.5 eV。这些氧物质在 Ar 气流中或在远紫外光照射下部分解吸，并在室温下的 O-2 气氛中再次重新吸附。这种强掺杂的石墨烯与通过无机酸侵蚀制成的“氧化石墨烯”有很大不同。
Patterned graphene shows substantial potential for applications in future molecular-scale integrated electronics. Environmental effects are a critical issue in a single-layer material where every atom is on the surface. Especially intriguing is the variety of rich chemical interactions shown by molecular oxygen with aromatic molecules. We find that O-2 etching kinetics vary strongly with the number of graphene layers in the sample. Three-layer-thick samples show etching similar to bulk natural graphite. Single-layer graphene reacts faster and shows random etch pits in contrast to natural graphite where nucleation occurs at point defects. In addition, basal plane oxygen species strongly hole dope graphene, with a Fermi level shift of similar to 0.5 eV. These oxygen species desorb partially in an Ar gas flow, or under irradiation by far UV light, and readsorb again in an O-2 atmosphere at room temperature. This strongly doped graphene is very different from "graphene oxide" made by mineral acid attack.