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arXiv 2007.14174cond-mat.mtrl-scicond-mat.mes-hall
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Graphene/TiO $_2$界面的电子结构:设计与功能展望

Electronic Structure of Graphene/TiO$_2$ Interface: Design and Functional Perspectives

Shashi B. Mishra, Somnath C. Roy, B. R. K. Nanda

摘要:

我们提出了低应变和能量有利的单层和双层石墨烯覆盖层的设计在TiO_2 $_2$(001)表面和检查的界面的电子结构的第一性原理计算的帮助。在没有表面TiO $_2$和石墨烯状态之间的杂化的情况下,偶极波动支配跨界面的微小电荷转移。结果,衬底和覆盖层都保持其原始的电子结构。与单层石墨烯的界面保持其无间隙的线性带色散,而不管诱导的外延应变。电势梯度在Bernal堆叠的情况下打开了几个meV的带隙,并且在双层石墨烯的六边形堆叠的情况下加强了狄拉克锥的互穿。异质结构中TiO $_2$和石墨烯层的宏观平均电势之间的差在3至3.13 eV的范围内,这非常接近TiO $_2$带隙($\sim$ 3.2 eV)。因此,所提出的异质结构将表现出增强的光诱导电荷转移,并且石墨烯组分将用作可见光敏化剂。

英文摘要:

We propose the design of low strained and energetically favourable mono and bilayer graphene overlayer on anatase TiO$_2$ (001) surface and examined the electronic structure of the interface with the aid of first principle calculations. In the absence of hybridization between surface TiO$_2$ and graphene states, dipolar fluctuations govern the minor charge transfer across the interface. As a result, both the substrate and the overlayer retain their pristine electronic structure. The interface with the monolayer graphene retains its gapless linear band dispersion irrespective of the induced epitaxial strain. The potential gradient opens up a few meV bandgap in the case of Bernal stacking and strengthens the interpenetration of the Dirac cones in the case of hexagonal stacking of the bilayer graphene. The difference between the macroscopic average potential of the TiO$_2$ and graphene layer(s) in the heterostructure lies in the range 3 to 3.13 eV, which is very close to the TiO$_2$ bandgap ($\sim$ 3.2 eV). Therefore, the proposed heterostructure will exhibit enhanced photo-induced charge transfer and the graphene component will serve as a visible light sensitizer.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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