Feng Li-ping, Su Jie, Li Da-peng, Liu Zheng-tang
State Key Lab of Solidification Processing, College of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, People's Republic of China.
Phys Chem Chem Phys. 2015 Mar 14;17(10):6700-4. doi: 10.1039/c5cp00008d.
The effect of vacancies in monolayer MoS2 on the electronic properties of a Ti-MoS2 top contact has been investigated using first-principles calculations. A Mo-vacancy is easier to form than a S-vacancy in a Ti-MoS2 top contact, especially under oxidation conditions. A Mo-vacancy eliminates the Schottky barrier of the Ti-MoS2 top contact, and a S-vacancy reduces the Schottky barrier from 0.28 to 0.15 eV. Mo-vacancies are beneficial for obtaining a high quality p-type Ti-MoS2 top contact, whereas S-vacancies are favorable to achieve a high quality n-type Ti-MoS2 top contact. Moreover, defective Ti-MoS2 top contacts have stronger dipole layers, a higher potential step and more transferred charges than a perfect ones. The electronic properties of Ti-MoS2 top contacts can be tuned by intrinsic vacancies in monolayer MoS2. Our findings provide important insights into the future design and fabrication of novel nanoelectronic devices with monolayer MoS2.
利用第一性原理计算研究了单层二硫化钼中的空位对Ti-MoS2顶部接触的电子性质的影响。在Ti-MoS2顶部接触中，Mo空位比S空位更容易形成，尤其是在氧化条件下。Mo空位消除了Ti-MoS2顶部接触的肖特基势垒，而S空位将肖特基势垒从0.28 eV降低到0.15 eV。Mo空位有利于获得高质量的p型Ti-MoS2顶部接触，而S空位有利于实现高质量的n型Ti-MoS2顶部接触。此外，有缺陷的Ti-MoS2顶部接触比完美的顶部接触具有更强的偶极层、更高的势垒和更多的转移电荷。单层二硫化钼中的固有空位可以调节Ti-MoS2顶部接触的电子性质。我们的研究结果为未来设计和制造具有单层二硫化钼的新型纳米电子器件提供了重要的见解。
