Lv Xingshuai, Wei Wei, Zhao Pei, Li Jinjin, Huang Baibiao, Dai Ying
School of Physics, State Key Laboratory of Crystal Materials, Shandong University, 250100 Jinan, P. R. China.
Phys Chem Chem Phys. 2018 Jan 17;20(3):1897-1903. doi: 10.1039/c7cp07546d.
The performance of electronic and optoelectronic devices based on two-dimensional (2D) materials could be significantly affected by the electrical contacts. In search of low-resistance contacts with transition-metal dichalcogenides (TMDs), we combine density functional calculations with quantum transport simulations to investigate the structural and electronic properties of the van der Waals (vdW) heterostructures MSe/NbSe (M = Mo and W). The formation of a p-type Schottky contact at the MSe/NbSe interface with small Schottky barriers (0.37 eV for MoSe/NbSe and 0.18 eV for WSe/NbSe) is demonstrated. The low Schottky barrier heights indicate a low contact resistance, which is beneficial for electron injection and low-resistance. Remarkably, we demonstrate that the Schottky barrier can be effectively tuned via the application of vertical compressive pressure, an external electrical field and tensile strain. Finally, the results are supported by quantum transport simulation, which further proves the highly transparent contacts and promising application potential in field-effect transistors (FET). Therefore, our formalism and findings not only provide insights into the MSe/NbSe interfaces but also help in the design of MSe monolayer-based devices.
基于二维（2D）材料的电子和光电器件的性能可能会受到电接触的显著影响。为了寻找与过渡金属二硫属化物（TMD）的低电阻接触，我们将密度泛函计算与量子输运模拟相结合，以研究范德华（vdW）异质结构MSe/NbSe（M = Mo和W）的结构和电子性质。结果表明，在MSe/NbSe界面处形成了具有小肖特基势垒（MoSe/NbSe为0.37 eV，WSe/NbSe为0.18 eV）的p型肖特基接触。低肖特基势垒高度表明接触电阻低，这有利于电子注入和低电阻。值得注意的是，我们证明了肖特基势垒可以通过施加垂直压缩压力、外部电场和拉伸应变来有效调节。最后，量子输运模拟支持了这些结果，进一步证明了其在场效应晶体管（FET）中的高透明接触和有前景的应用潜力。因此，我们的形式主义和发现不仅为MSe/NbSe界面提供了见解，也有助于基于MSe单层的器件设计。
