Probing disorder and charged impurities in graphene by Raman spectroscopy
Probing disorder and charged impurities in graphene by Raman spectroscopy
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DOI：
10.1002/pssr.200903135
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发表时间：
2009-09-01
影响因子：
2.8
通讯作者：
Casiraghi, Cinzia
中科院分区：
文献类型：
--
作者：
Casiraghi, Cinzia
无序和掺杂会严重影响石墨烯的性能。本文用拉曼光谱分析了这些效应对几种样品的影响。特别是，我们发现原始的和未加工的石墨烯样品沉积在硅上，覆盖一层薄薄的氧化硅层，即使在没有无序的情况下，它们的拉曼光谱也表现出强烈的变化。拉曼参数的变化归因于带电杂质。这表明沉积的石墨烯是无意中掺杂的，在环境条件下达到10(13)cm（-2）的电荷浓度。不同样品的掺杂情况不同，在亚微米尺度上电荷分布不均匀。(c) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Disorder and doping can strongly affect the properties of graphene. Here we analyze these effects on several samples by Raman spectroscopy. In particular, we show that pristine and unprocessed graphene samples deposited on silicon, covered with a thin silicon oxide layer, show strong variations in their Raman spectra, even in absence of disorder. The variation in the Raman parameters is assigned to charged impurities. This shows that as-deposited graphene is unintentionally doped, reaching charge concentrations up to 10(13) cm(-2) under ambient conditions. The doping varies from sample to sample and the charges are inhomogeneously distributed on a submicron scale. (c) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim