Monitoring dopants by Raman scattering in an electrochemically top-gated graphene transistor
Monitoring dopants by Raman scattering in an electrochemically top-gated graphene transistor
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DOI：
10.1038/nnano.2008.67
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发表时间：
2008-04-01
影响因子：
38.3
通讯作者：
Sood, A. K.
中科院分区：
文献类型：
--
作者：
Das, A.;Pisana, S.;Sood, A. K.
最近发现的石墨烯（1-3）导致了二维物理和设备（4，5）的许多进展。迄今为止制造的石墨烯器件依赖于SiO2背栅（1-3）。电化学顶栅广泛用于聚合物晶体管（6，7），也已成功应用于碳纳米管（8，9）。在这里，我们展示了一种顶栅石墨烯晶体管，它能够达到高达5x 10（13）cm（-2）的掺杂水平，这比以前报道的要高得多。这样的高掺杂水平是可能的，因为固体聚合物电解质栅极中的纳米厚德拜层（8，10）提供比通常使用的SiO2背栅极（其通常为约300 nm厚（11））高得多的栅极电容。原位拉曼测量监测掺杂。对于电子和空穴掺杂，G峰变硬并且变尖，但是2D峰示出对空穴和电子的不同响应。G峰和2D峰的强度比显示出对掺杂的强烈依赖性，使其成为监测掺杂的敏感参数。
The recent discovery of graphene(1-3) has led to many advances in two-dimensional physics and devices(4,5). The graphene devices fabricated so far have relied on SiO2 back gating(1-3). Electrochemical top gating is widely used for polymer transistors(6,7), and has also been successfully applied to carbon nanotubes(8,9). Here we demonstrate a top-gated graphene transistor that is able to reach doping levels of up to 5x10(13) cm(-2), which is much higher than those previously reported. Such high doping levels are possible because the nanometre-thick Debye layer(8,10) in the solid polymer electrolyte gate provides a much higher gate capacitance than the commonly used SiO2 back gate, which is usually about 300 nm thick(11). In situ Raman measurements monitor the doping. The G peak stiffens and sharpens for both electron and hole doping, but the 2D peak shows a different response to holes and electrons. The ratio of the intensities of the G and 2D peaks shows a strong dependence on doping, making it a sensitive parameter to monitor the doping.