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Two-dimensional (2D) materials possess great potential in applications to the next-generation nanoelectronics and optoelectronics. Van der Waals heterostructures composed by different 2D materials provide additional possibility to access nanoelectronic devices with great properties. A recent research has unraveled the evolution of electronic structures of a set of vdW heterostructures under an applied vertical electric field.
The related article entitled “The Coulomb interaction in van der Waals heterostructures” has been published in 2019 (3) issue of SCIENCE CHINA: Physics, Mechnics & Astronomy with Prof. Jingbo Li (School of Materials and Energy, Guangdong University of Technology) and Prof. Su-Huai Wei (Beijing Computational Science Research Center) as the corresponding authors. The researchers have studied the electronic structures of a set of vdW heterostructures and the effect of applied vertical electric field. It has been revealed that the Coulomb interaction plays an important role in the giant Stark effect of vdW heterostructures.
The segmentation of various two-dimensional (2D) materials makes it possible to construct the van der Waals (vdW) heterostructures, which provide more opportunities for achieving desired electronic or optoelectronic properties. Tuning the optoelectronic properties of vdW heterostructures in a controllable way is a key factor underlying nanoscience and nanotechnology. To modify their electronic properties, gate voltages are usually utilized in related nanoelectronics and optoelectronics.
In this article, researchers have performed first-principles calculations to study the electronic structures of vdW heterostructures and the effect of applied vertical electric field on the bandedges. A general linear giant Stark effect is revealed. This work focuses on the nonlinear variation of the bandedges of vdW heterostructures when subjected to a weak electric field. This nonlinear variation is attributed to the Coulomb interaction induced by the interlayer charge transfer.
This research enriched the research on 2D vdW heterostructures. It offered a new insight into the mechanism of the nonlinear giant Stark effect in vdW heterostructures, which is important for the applications of vdW heterostructures on nanoelectronic devices.