基于密度泛函理论的第一性原理计算用于研究石墨烯插入对MoS2/金属的电子性质和肖特基势垒的影响(Mg,Al,In,Cu,Ag,Au,Pd,Ti,和Sc)而不会劣化MoS2层的固有特性。结果表明,电荷转移主要发生在石墨烯与金属层之间的界面,在双层石墨烯之间或石墨烯和MoS2之间的界面处具有较小的转移。在石墨烯与MoS2的界面存在隧穿势垒,阻碍了电子从石墨烯注入到MoS2。重要的是,肖特基势垒高度(ΦSB,N)在石墨烯插入MoS2/金属触点时降低。具体来说,对于单层石墨烯,ΦSB,与Mg接触的MoS2的N,In,Sc,Ti为-0.116eV,-0.116eV,-0.014eV,和-0.116eV,分别。此外,用双层石墨烯,当插入双层石墨烯时,-0.086eV的负n型肖特基势垒,-0.114eV,-0.059eV,-0.008eV,对于与相应金属接触的MoS2,观察到-0.0636eV,分别。这些发现为开发和设计高性能过渡金属二硫属纳米电子器件提供了实践指导。
First-principle calculations based on density functional theory are employed to investigate the impact of graphene insertion on the electronic properties and Schottky barrier of MoS2/metals (Mg, Al, In, Cu, Ag, Au, Pd, Ti, and Sc) without deteriorating the intrinsic properties of the MoS2 layer. The results reveal that the charge transfer mainly occurs at the interface between the graphene and metal layers, with smaller transfer at the interface between bi-layer garphene or between graphene and MoS2. And the tunneling barrier exists at the interface between graphene and MoS2, which hinders electron injection from graphene to MoS2. Importantly, the Schottky barrier height ( Φ SB,N ) decreases upon graphene insertion into MoS2/metal contacts. Specifically, for single-layer graphene, the Φ SB,N of MoS2 contacted with Mg, In, Sc, and Ti are - 0.116 eV, - 0.116 eV, - 0.014 eV, and - 0.116 eV, respectively. Furthermore, with bilayer graphene, when by inserting bi-layer graphene, the negative n-type Schottky barrier of - 0.086 eV, - 0.114 eV, - 0.059 eV, - 0.008 eV, and - 0.0636 eV are observed for MoS2 contacted with the respective metals, respectively. These findings provide a practical guidance for developing and designing high-performance transition metal dichalcogenide nanoelectronic devices.