Direct Observation of Inter layer Hybridization and Dirac Relativistic Carriers in Graphene/MoS2 van der Waals Heterostructures
Direct Observation of Inter layer Hybridization and Dirac Relativistic Carriers in Graphene/MoS2 van der Waals Heterostructures
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DOI：
10.1021/nl504167y
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发表时间：
2015-02-01
期刊：
影响因子：
10.8
通讯作者：
Batzill, Matthias
中科院分区：
文献类型：
--
作者：
Diaz, Horacio Coy;Avila, Jose;Batzill, Matthias
由范德华材料组装的人工异质结构有望结合材料，而不受传统异质结构生长的限制，如晶格匹配条件和原子相互扩散。将具有不同性质的范德华材料简单地堆叠在一起，就可以制造出具有原子精确界面的新型材料或器件结构。由于这些层状材料中的共价键仅限于分子平面，并且平面之间的相互作用非常弱，因此将这些材料堆叠在一起只会导致电子结构的微小变化。在这里，我们制备了cvd生长的石墨烯和MoS2之间的界面，并报道了用角分辨光电发射光谱直接测量这种范德华异质结构的电子结构。虽然石墨烯的狄拉克锥保持完整，没有检测到明显的电荷转移掺杂，但我们观察到石墨烯的p带形成了带隙，远离费米能级，由于与MoS2衬底的态杂化。
Artificial heterostructures assembled from van der Waals materials promise to combine materials without the traditional restrictions in heterostructure-growth such as lattice matching conditions and atom interdiffusion. Simple stacking of van der Waals materials with diverse properties would thus enable the fabrication of novel materials or device structures with atomically precise interfaces. Because covalent bonding in these layered materials is limited to molecular planes and the interaction between planes are very weak, only small changes in the electronic structure are expected by stacking these materials on top of each other. Here we prepare interfaces between CVD-grown graphene and MoS2 and report the direct measurement of the electronic structure of such a van der Waals heterostructure by angle-resolved photoemission spectroscopy. While the Dirac cone of graphene remains intact and no significant charge transfer doping is detected, we observe formation of band gaps in the p-band of graphene, away from the Fermi-level, due to hybridization with states from the MoS2 substrate.