Li Ying, Xu Lianqiang, Yang Chen, Xu Linqiang, Liu Shiqi, Yang Zongmeng, Li Qiuhui, Dong Jichao, Yang Jie, Lu Jing
State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871, P. R. China.
School of Physics and Electronic Information Engineering, Engineering Research Center of Nanostructure and Functional Materials, Ningxia Normal University, Guyuan 756000, China.
ACS Appl Mater Interfaces. 2024 Sep 18;16(37):49496-49507. doi: 10.1021/acsami.4c09880. Epub 2024 Sep 4.
The latest synthesized monolayer (ML) MoSiN material exhibits stability in ambient conditions, suitable bandgap, and high mobilities. Its potential as a next-generation transistor channel material has been demonstrated through quantum transport simulations. However, in practical two-dimensional (2D) material transistors, the electrical contacts formed by the channel and the electrode must be optimized, as they are crucial for determining the efficiency of carrier injection. We employed the density functional theory (DFT) combined with the nonequilibrium Green's function (NEGF) method to systematically explore the vertical and horizontal interfaces between the typical metal electrodes and the ML MoSiN. The DFT+NEGF method incorporates the coupling between the electrode and the channel, which is crucial for quantum transport. Among these metals, Sc and Ti form -type Ohmic contacts with zero tunneling barriers at both vertical and horizontal interfaces with ML MoSiN, making them optimal for contact metals. In-ML MoSiN contacts display zero Schottky barriers but a 3.11 eV tunneling barrier. Cu and Au establish -type Schottky contacts, while Pt forms a -type contact. The Fermi pinning factors of the metal-ML MoSiN contacts for both electrons and holes are above 0.51, much higher than the typical 2D semiconductors. Moreover, there is a strong positive correlation between the Fermi pinning factor and the band gap, with a Spearman rank correlation coefficient of 0.897 and a -value below 0.001. Our work provides insight into the contact optimization for the ML MoSiN transistors and highlights the promising potential of ML MoSiN as the channel material for the next-generation FETs.
最新合成的单层（ML）MoSiN材料在环境条件下表现出稳定性、合适的带隙和高迁移率。通过量子输运模拟已经证明了其作为下一代晶体管沟道材料的潜力。然而，在实际的二维（2D）材料晶体管中，由沟道和电极形成的电接触必须进行优化，因为它们对于确定载流子注入效率至关重要。我们采用密度泛函理论（DFT）结合非平衡格林函数（NEGF）方法，系统地探索了典型金属电极与ML MoSiN之间的垂直和水平界面。DFT + NEGF方法考虑了电极与沟道之间的耦合，这对于量子输运至关重要。在这些金属中，Sc和Ti在与ML MoSiN的垂直和水平界面处均形成具有零隧穿势垒的n型欧姆接触，使其成为接触金属的最佳选择。In-ML MoSiN接触显示零肖特基势垒，但有3.11 eV的隧穿势垒。Cu和Au形成p型肖特基接触，而Pt形成n型接触。金属-ML MoSiN接触对于电子和空穴的费米钉扎因子均高于0.51，远高于典型的二维半导体。此外，费米钉扎因子与带隙之间存在很强的正相关性，斯皮尔曼等级相关系数为0.897，p值低于0.001。我们的工作为ML MoSiN晶体管的接触优化提供了见解，并突出了ML MoSiN作为下一代场效应晶体管沟道材料的广阔前景。
