论文标题
扭曲的H-BN/石墨烯异质结构中的可调式间横向过渡
Tunable Interband Transitions in Twisted h-BN/Graphene Heterostructures
论文作者
论文摘要
在扭曲的H-BN/石墨烯异质结构中，通常认为石墨烯中快速旅行电子气体的复杂电子性能被认为是完全揭示的。但是，随机扭曲的异质结构也可能具有意外的过渡行为，这可能会影响设备性能。在这里，我们研究了使用单色电子能量损失光谱法研究H-BN/石墨烯异质结构的扭角依赖性耦合效应。我们发现Moiré电位改变了石墨烯的带状结构，从而导致M-Point的内延型转变的红移，随着扭转角的增加，它的变化更加明显到0.25 eV。此外，H-BN相对于石墨烯M点的Brillouin区域的扭曲导致可调垂直过渡能在5.1-5.6 eV范围内。我们的发现表明，应在设备制造中仔细考虑Van der Waals异质结构的扭曲耦合效应，并且通过扭转角的连续可调式间跨性别跃迁可以作为设计光电设备的新自由度。
In twisted h-BN/graphene heterostructures, the complex electronic properties of the fast-traveling electron gas in graphene are usually considered to be fully revealed. However, the randomly twisted heterostructures may also have unexpected transition behaviors, which may influence the device performance. Here, we study the twist angle-dependent coupling effects of h-BN/graphene heterostructures using monochromatic electron energy loss spectroscopy. We find that the moiré potentials alter the band structure of graphene, resulting in a redshift of the intralayer transition at the M-point, which becomes more pronounced up to 0.25 eV with increasing twist angle. Furthermore, the twisting of the Brillouin zone of h-BN relative to the graphene M-point leads to tunable vertical transition energies in the range of 5.1-5.6 eV. Our findings indicate that twist-coupling effects of van der Waals heterostructures should be carefully considered in device fabrications, and the continuously tunable interband transitions through the twist angle can serve as a new degree of freedom to design optoelectrical devices.
