Song Shun, Gong Jian, Jiang Xiangwei, Yang Shenyuan
School of Physics and Technology, Inner Mongolia University, Hohhot 010021, P. R. China.
State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, P. R. China.
Phys Chem Chem Phys. 2022 Jan 26;24(4):2265-2274. doi: 10.1039/d1cp04502d.
We systematically study the influence of interface configuration and strain on the electronic and transport properties of lateral MoS/graphene heterostructures by first-principles calculations and quantum transport simulations. We first identify the favorable heterostructure configurations with C-S and/or C-Mo bonds at the interfaces. Strain can be applied to graphene or MoS and would not change the relative stabilities of different heterostructures. Band alignment calculations show that all the lateral heterostructures have n-type Schottky contacts. The current-voltage characteristics of the lateral MoS/graphene heterostructure diodes exhibit good rectification performance. Too strong and too weak interface interactions do not benefit electronic transport. The MoS/graphene heterostructures with moderate C-S bonds at the interface have larger currents through the junctions than those with C-Mo bonds at the interface. The maximal rectification ratio of the lateral diode with strain applied to MoS can reach up to 10. With strain applied to graphene, the currents through the heterostructures can increase by 1-2 orders of magnitude due to the reduced Schottky barrier heights at the interface, but the rectification ratio is reduced with a maximal value of 10. Our calculations can serve as a theoretical guide to design rectifier and diode devices based on two-dimensional lateral heterostructures.
我们通过第一性原理计算和量子输运模拟，系统地研究了界面构型和应变对横向MoS/石墨烯异质结构的电子和输运性质的影响。我们首先确定了界面处具有C-S和/或C-Mo键的有利异质结构构型。应变可以施加到石墨烯或MoS上，并且不会改变不同异质结构的相对稳定性。能带排列计算表明，所有横向异质结构都具有n型肖特基接触。横向MoS/石墨烯异质结构二极管的电流-电压特性表现出良好的整流性能。过强和过弱的界面相互作用都不利于电子输运。界面处具有适度C-S键的MoS/石墨烯异质结构通过结的电流比界面处具有C-Mo键的异质结构更大。对MoS施加应变的横向二极管的最大整流比可达10。对石墨烯施加应变时，由于界面处肖特基势垒高度降低，通过异质结构的电流可增加1-2个数量级，但整流比降低，最大值为10。我们的计算可为基于二维横向异质结构设计整流器和二极管器件提供理论指导。
