Mapping electronic states of triple anti-parallel and symmetric zigzag grain boundaries of graphene on highly oriented pyrolytic graphite
Mapping electronic states of triple anti-parallel and symmetric zigzag grain boundaries of graphene on highly oriented pyrolytic graphite
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在高取向热解石墨上绘制石墨烯三重反平行和对称之字形晶界的电子态
DOI：
10.1016/j.cplett.2017.12.020
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发表时间：
2017-09
影响因子：
2.8
通讯作者：
Dou R. F.
中科院分区：
文献类型：
--
作者：
Ma J.;Li X. Y.;Yin L. J.;Wang W. X.;Sun Q.;Yang Y.;Zhang P.;Nie J. C.;Xiong C. M.;Dou R. F.
石墨烯表面的晶界被广泛研究，因为具有特定缺陷构型的晶界会形成新的弯曲结构，可以作为新的碳同素异形体处理。用扫描隧道显微镜和扫描电子显微镜(STM/S)研究了石墨烯中的两个周期晶格在高取向热解石墨表面的结构和电子光谱。我们的结果表明，由五角-七角(5-7)碳环的两个平行周期位错核组成的Gb在石墨烯表面Dirac点上方0.45 eV处产生了增强的局域态，这归因于van Hove奇点(VHS)。局域态的能级位置随位置的不同在0.40~0.47 eV之间变化，最终衰变到0.36 eV。这种能级位置的变化是由两个平行的Gb引起的，这是因为作为缺陷中心的Gb处的电子密度较高，而远离Gb的电子密度较低。另一个具有对称之字形结构特征的周期晶格在费米能级附近产生了-0.038和0.12 eV的超高速。此外，在这两个基团上都观察到了谷间散射。这意味着载流子浓度和周期性能级周围的电导可以通过局域态密度显著提高。这一发现表明，适当嵌入有序GB的石墨烯有望改善基于石墨烯的电子器件的性能。
The grain boundaries (GBs) of a graphene surface were extensively studied because GBs with specific defect configurations result in the formation of new curved structures, which can be treated as new carbon allotropes. We studied the structures and electronic spectra of two periodic GBs in graphene on highly oriented pyrolytic graphite (HOPG) surfaces using scanning tunneling microscopy and spectroscopy (STM/S). Our results demonstrated that a GB consisting of dual parallel periodic dislocation cores of pentagonal-heptagonal (5-7) carbon rings gives rise to an enhanced localized state at 0.45 eV above the Dirac point in graphene surfaces, which is attributed to van Hove singularities (VHSs). Moreover, the energy positions of the localized states are varied between 0.40 and 0.47 eV depending on the site and eventually decayed to 0.36 eV. The variation of the energy positions is induced by two parallel GBs because of the higher electron density at the GB as a defect center and the lower electron away from the GB. Another periodic GB with a symmetric zigzag structural feature induced VHSs at -0.038 and 0.12 eV near the Fermi level. Moreover, intervalley scattering was observed on both these GBs. This means that carrier concentration and thus, the conductance around the periodic GBs can be significantly enhanced by localized density of states. This finding suggests that graphene with a properly embedded ordered GB is promising for improving the performance of graphene-based electronic devices.
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影响因子：
6.7
作者：
Chuanxu Ma;Haifeng Sun;Hongjian Du;Jufeng Wang;A. Zhao;Qunxiang Li;B. Wang;J. Hou
通讯作者：
Chuanxu Ma;Haifeng Sun;Hongjian Du;Jufeng Wang;A. Zhao;Qunxiang Li;B. Wang;J. Hou
影响因子：
3.7
作者：
Carlsson, Johan M.;Ghiringhelli, Luca M.;Fasolino, Annalisa
通讯作者：
Fasolino, Annalisa
影响因子：
10.8
作者：
Rasool, Haider I.;Ophus, Colin;Zettl, Alex
通讯作者：
Zettl, Alex
影响因子：
3.3
作者：
Biro, Laszlo P.;Lambin, Philippe
通讯作者：
Lambin, Philippe
对称和非对称石墨烯晶界的结构和电子性质
影响因子：
10.9
作者：
Zhang, Junfeng;Zhao, Jijun
通讯作者：
Zhao, Jijun