Graphene-based van der Waals heterostructures are expected recently to design and fabricate many novel electronic and optoelectronic devices. The combination of the electronic structures of graphene and graphene-like GaSe monolayer (g-GaSe) in an ultrathin heterostructure has been realized experimentally, such as graphene/g-GaSe field effect transistor and dual Schottky diode device. In the present work, we investigate the electronic properties of the graphene/g-GaSe heterostructures under the applied electric field, in-plane strains, and interlayer coupling. Our results show that the electronic properties of the graphene/g-GaSe heterostructures are well preserved owing to a weak vdW interaction. Especially, a tiny band gap of 13 meV has opened in the presence of the g-GaSe monolayer. We found that the n-type Schottky contact is formed in the graphene/g-GaSe heterostructure with a Schottky barrier height of 0.86 eV, which can be efficiently modulated by applying the electric field, in-plane strains, and interlayer coupling. Furthermore, a transformation from the n-type to p-type Schottky contact is observed when the applied electric field is larger than 0.1 V/Å or the interlayer distance is smaller than 3.2 Å. Our results may provide helpful information to design and fabricate the future graphene-based vdW heterostructures, such as graphene/g-GaSe heterostructure and understand the physics mechanism in the graphene-based 2D vdW heterostructures.

最近期望基于石墨烯的范德华异质结构设计和制造许多新颖的电子和光电器件。已经通过实验实现了石墨烯和石墨烯状的GaSe单层（g -GaSe）的电子结构在超薄异质结构中的组合，例如石墨烯/ g -GaSe场效应晶体管和双肖特基二极管器件。在本工作中，我们研究了石墨烯/ g -GaSe异质结构在施加电场，面内应变和层间耦合作用下的电子性能。我们的结果表明，石墨烯的电子性能/ g由于弱的vdW相互作用，-GaSe异质结构得到了很好的保存。特别地，在存在g -GaSe单层的情况下，已经打开了13 meV的微小带隙。我们发现，在石墨烯/ g -GaSe异质结构中形成了n型肖特基接触，肖特基势垒高度为0.86 eV，可以通过施加电场，面内应变和层间耦合有效地对其进行调制。此外，从n型到p的转换当施加的电场大于0.1 V /Å或层间距离小于3.2Å时，会观察到肖特基接触。我们的结果可能为设计和制造未来的基于石墨烯的vdW异质结构（例如石墨烯/ g -GaSe异质结构）提供有用的信息，并了解基于石墨烯的2d vdW异质结构的物理机理。