Intercalation of Few-Layer Graphite Flakes with FeCl3: Raman Determination of Fermi Level, Layer by Layer Decoupling, and Stability
Intercalation of Few-Layer Graphite Flakes with FeCl3: Raman Determination of Fermi Level, Layer by Layer Decoupling, and Stability
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FeCl3 插层少层石墨片：费米能级的拉曼测定、逐层解耦和稳定性
DOI：
10.1021/ja110939a
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发表时间：
2011-04-20
影响因子：
15
通讯作者：
Ferrari, Andrea C.
中科院分区：
文献类型：
--
作者：
Zhao, Weijie;Tan, Ping Heng;Ferrari, Andrea C.
我们使用无水氯化铁（FeCl 3）来插层由2-4个石墨烯层组成的石墨薄片并掺杂石墨烯单层。通过拉曼散射表征所得插层化合物（IC）的插层剂、分级、稳定性和掺杂。重掺杂单层石墨烯的G峰上移至类似于1627 cm（-1）。2-4层IC具有类似的上移，并且洛伦兹线去耦重掺杂单层。通过执行拉曼形状的2D带，表明每个层的行为作为一个测量在不同的激发能量，我们表明，对于一个给定的掺杂水平，2D峰值可以抑制泡利阻挡激光能量低于掺杂水平。因此，多波长拉曼光谱允许直接测量费米能级，与通过在显著高于掺杂能级的固定激发能量下进行测量而得到的费米能级互补。这使我们能够估计费米能级位移高达0.9 eV。因此，这些IC是重掺杂石墨烯物理和化学性质的理想测试平台。
We use anhydrous ferric chloride (FeCl3) to intercalate graphite flakes consisting of 2-4 graphene layers and to dope graphene monolayers. The intercalant, staging, stability, and doping of the resulting intercalation compounds (ICs) are characterized by Raman scattering. The G peak of heavily doped monolayer graphene upshifts to similar to 1627 cm(-1). The 2-4 layer ICs have similar upshifts, and a Lorentzian line decoupled heavily doped monolayer. By performing Raman shape for the 2D band, indicating that each layer behaves as a measurements at different excitation energies, we show that, for a given doping level, the 2D peak can be suppressed by Pauli blocking for laser energy below the doping level. Thus, multiwavelength Raman spectroscopy allows a direct measurement of the Fermi level, complementary to that derived by performing measurements at fixed excitation energy significantly higher than the doping level. This allows us to estimate a Fermi level shift of up to similar to 0.9 eV. These ICs are thus ideal test-beds for the physical and chemical properties of heavily doped graphenes.