Modulation of the band gap of graphene oxide: The role of AA-stacking
Modulation of the band gap of graphene oxide: The role of AA-stacking
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DOI：
10.1016/j.carbon.2013.09.036
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发表时间：
2014-01-01
期刊：
影响因子：
10.9
通讯作者：
Moewes, A.
中科院分区：
文献类型：
--
作者：
Hunt, A.;Dikin, D. A.;Moewes, A.
石墨烯独特的电子性质使其成为许多应用中使用的有利材料，除了那些需要带隙的应用。人们已经做了很多工作来将适当调整的带隙引入石墨烯，包括单轴应变和氧化，取得了不同程度的成功。我们在这里报告说，在多层氧化石墨烯片的堆叠配置可以有显着的影响带隙。通过比较多层原始石墨烯片的X射线吸收近边光谱与使用密度泛函理论模拟的光谱，我们发现AA堆叠通过加宽氧化石墨烯和石墨烯中的π * 共振而比AB堆叠更接近费米能级。如果近费米态已经被去除，使得离费米能级最近的未占据态是π * 带，则AA堆叠的多层氧化石墨烯将具有比AB堆叠的氧化石墨烯更小的带隙。我们已经通过使用X射线吸收近边光谱和X射线发射光谱间接测量氧化石墨烯和还原氧化石墨烯的带隙证实了这一点。控制多层氧化石墨烯的堆叠配置可以提供用于调节其带隙的新方法。(C)2013爱思唯尔有限公司保留所有权利。
The unique electronic properties of graphene make it an advantageous material for use in many applications, except those that require a band gap. Much work has been done to introduce an appropriately tuned band gap into graphene, including uniaxial strain and oxidation, with varying levels of success. We report here that the stacking configuration of the sheets in multilayered graphene oxide can have a significant impact on the band gap. Through comparison of X-ray absorption near-edge spectra of multilayered pristine graphene sheets with spectra simulated using density functional theory, we have found that AA-stacking pushes unoccupied states closer to the Fermi level than AB-stacking by widening the pi* resonance in both graphene oxide and graphene. If the near-Fermi states have been removed such that the nearest unoccupied state to the Fermi level is the pi* band, then AA-stacked multilayered graphene oxide will have a smaller band gap than AB-stacked graphene oxide. We have confirmed this by measuring the band gap of graphene oxide and reduced graphene oxide indirectly using X-ray absorption near-edge spectroscopy and X-ray emission spectroscopy. Controlling the stacking configuration of multilayered graphene oxide may provide a novel method for tuning its band gap. (C) 2013 Elsevier Ltd. All rights reserved.