Influence of metal contacts and charge inhomogeneity on transport properties of graphene near the neutrality point
Influence of metal contacts and charge inhomogeneity on transport properties of graphene near the neutrality point
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DOI：
10.1016/j.ssc.2009.02.039
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发表时间：
2009-07-01
影响因子：
2.1
通讯作者：
Geim, A. K.
中科院分区：
文献类型：
--
作者：
Blake, P.;Yang, R.;Geim, A. K.
关于石墨烯在中性点附近的电子特性的文献数量日益增多。许多实验仍在使用双探针结构或侵入式接触，或者没有控制样品的宏观均匀性。我们认为指出与这类测量相关的一些问题是有帮助的。通过实验实例，我们说明由杂质化学掺杂或金属接触引起的电荷不均匀性会在评估石墨烯的输运特性，特别是其最小电导率时导致较大的系统误差。在双探针测量的情况下，这些问题最为严重，因为发现接触电阻会随着栅极电压强烈变化。（C）2009爱思唯尔有限公司。保留所有权利。
There is an increasing amount of literature concerning electronic properties of graphene close to the neutrality point. Many experiments continue using the two-probe geometry or invasive contacts or do not control samples' macroscopic homogeneity. We believe that it is helpful to point out some problems related to such measurements. By using experimental examples, we illustrate that the charge inhomogeneity induced by spurious chemical doping or metal contacts can lead to large systematic errors in assessing graphene's transport properties and, in particular, its minimal conductivity. The problems are most severe in the case of two-probe measurements where the contact resistance is found to strongly vary as a function of gate voltage. (C) 2009 Elsevier Ltd. All rights reserved.