Spin-polarized Fermi surface, hole-doping and band gap in graphene with boron impurities.
Spin-polarized Fermi surface, hole-doping and band gap in graphene with boron impurities.
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DOI：
10.1039/c8nr08339h
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发表时间：
2018-12
期刊：
影响因子：
6.7
通讯作者：
A. Fedorov;L. Yashina;O. Vilkov;C. Laubschat;D. Vyalikh;D. Usachov
中科院分区：
文献类型：
--
作者：
A. Fedorov;L. Yashina;O. Vilkov;C. Laubschat;D. Vyalikh;D. Usachov
在石墨烯中嵌入杂质原子和交换衬底被证明是控制石墨烯性质的有效方法。结合ARPES实验和DFT计算，我们发现在Co（0001）衬底上通过化学气相沉积（CVD）生长的硼掺杂石墨烯（B-graphene）变成空穴掺杂，其费米面在K点附近显示出强的自旋极化态。后者源于自旋极化的迷你狄拉克锥，这是石墨烯/Co（0001）界面的固有二维特征，并且由C 2 pz和Co 3d态的混合物形成。由于CVD方法允许实现高达20原子%的结合B原子，这为处理系统的自旋极化性质提供了一定的灵活性。我们还表明，B-石墨烯层与Co（0001）衬底的键合可以通过Li嵌入到界面中来释放。这允许详细探索掺杂效应。最后，我们的ARPES数据表明，作为两个石墨烯亚晶格中高度不平衡的硼浓度的结果，狄拉克锥中的间隙开口。
Embedding foreign atoms in graphene and interchanging the underlying substrate are proved to be efficient methods for manipulating the properties of graphene. Combining ARPES experiments with DFT calculations we show that boron-doped graphene (B-graphene) grown on a Co(0001) substrate by chemical vapor deposition (CVD) becomes hole doped and its Fermi surface near the K-point reveals strongly spin-polarized states. The latter stems from the spin-polarized mini Dirac cone that is an intrinsic two-dimensional feature of the graphene/Co(0001) interface and is formed by a mixture of C 2pz and Co 3d states. Since the CVD method allows the achievement of up to 20 at% of incorporated B atoms, this provides a certain flexibility for handling the spin-polarized properties of the system. We also show that the bonding of the B-graphene layer to the Co(0001) substrate can be released by intercalation of Li into the interface. This allows the exploration of the doping effect in detail. Finally, our ARPES data indicate a gap opening in the Dirac cone as a result of the highly unbalanced boron concentrations in the two graphene sublattices.