Ju Weiwei, Wang Donghui, Zhou Qingxiao, Kang Dawei, Li Tongwei, Hu Guangxiong, Li Haisheng
College of Physics and Engineering, Henan University of Science and Technology, Luoyang 471023, China.
Provincial and Ministerial Co-construction of Collaborative Innovation Center for Non-ferrous Metal New Materials and Advanced Processing Technology, Luoyang 471023, China.
Phys Chem Chem Phys. 2021 Sep 15;23(35):19297-19307. doi: 10.1039/d1cp01292d.
The electrical contact and graphene (Gr) doping for Gr/XPtY (X, Y = S, Se, and Te) van der Waals (vdW) heterostructures are studied by using first-principles methods. The intrinsic electronic properties of Gr and PtXY are preserved due to the weak vdW interactions. We find that the types of interfacial electrical contact and Gr doping are closely related to the interface chalcogen atoms. The n-type Ohmic contact is formed in the Gr/SPtY (Y = S, Se, and Te) systems. The n-type and p-type Schottky contacts are realized in the Gr/SePtY and Gr/TePtY systems, respectively. The physical mechanism of different contact types can be analyzed based on the charge transfer between the Gr and XPtY layers. For all the heterostructures, the contact type and Schottky barrier height can be effectively modulated by the external electric field and interlayer coupling. The Gr doping type and charge-carrier concentration are also investigated. The p-doping, p-doping, and n-doping are obtained in Gr for the Gr/SPtY, Gr/SePtY, and Gr/TePtY systems, respectively. The highest carrier concentration of the Gr layer can reach 1.69 × 10 cm for the Gr/TePtTe system. The results indicate that Gr/XPtY heterostructures are potential candidates for improving the performance of high-efficiency nano electronic devices.
通过第一性原理方法研究了Gr/XPtY（X、Y = S、Se和Te）范德华（vdW）异质结构的电接触和石墨烯（Gr）掺杂。由于弱范德华相互作用，Gr和PtXY的本征电子性质得以保留。我们发现界面电接触和Gr掺杂的类型与界面硫族原子密切相关。在Gr/SPtY（Y = S、Se和Te）体系中形成了n型欧姆接触。在Gr/SePtY和Gr/TePtY体系中分别实现了n型和p型肖特基接触。基于Gr和XPtY层之间的电荷转移，可以分析不同接触类型的物理机制。对于所有异质结构，接触类型和肖特基势垒高度可以通过外部电场和层间耦合有效地调制。还研究了Gr掺杂类型和电荷载流子浓度。对于Gr/SPtY、Gr/SePtY和Gr/TePtY体系，在Gr中分别获得了p型掺杂、p型掺杂和n型掺杂。对于Gr/TePtTe体系，Gr层的最高载流子浓度可达1.69×10 cm。结果表明，Gr/XPtY异质结构是提高高效纳米电子器件性能的潜在候选材料。
