Singh Amit, Lee Seunghan, Bae Hyeonhu, Koo Jahyun, Yang Li, Lee Hoonkyung
Department of Physics, Konkuk University Seoul 05029 Korea
Department of Mechanical Engineering, National Chiao Tung University Hsinchu 300 Taiwan Republic of China.
RSC Adv. 2019 Dec 4;9(69):40309-40315. doi: 10.1039/c9ra07700f. eCollection 2019 Dec 3.
First-principle calculations were employed to analyze the effects induced by vacancies of molybdenum (Mo) and sulfur (S) on the dielectric properties of few-layered MoS. We explored the combined effects of vacancies and dipole interactions on the dielectric properties of few-layered MoS. In the presence of dielectric screening, we investigated uniformly distributed Mo and S vacancies, and then considered the case of concentrated vacancies. Our results show that the dielectric screening remarkably depends on the distribution of vacancies owing to the polarization induced by the vacancies and on the interlayer distances. This conclusion was validated for a wide range of wide-gap semiconductors with different positions and distributions of vacancies, providing an effective and reliable method for calculating and predicting electrostatic screening of dimensionally reduced materials. We further provided a method for engineering the dielectric constant by changing the interlayer distance, tuning the number of vacancies and the distribution of vacancies in few-layered van der Waals materials for their application in nanodevices and supercapacitors.
采用第一性原理计算方法，分析了钼（Mo）和硫（S）空位对少层MoS介电性能的影响。我们探究了空位和偶极相互作用对少层MoS介电性能的综合影响。在存在介电屏蔽的情况下，我们研究了均匀分布的Mo和S空位，然后考虑了空位集中的情况。我们的结果表明，由于空位引起的极化以及层间距离，介电屏蔽显著取决于空位的分布。这一结论在具有不同空位位置和分布的各种宽禁带半导体中得到了验证，为计算和预测维度降低材料的静电屏蔽提供了一种有效且可靠的方法。我们还进一步提供了一种通过改变层间距离、调整少层范德华材料中空位的数量和分布来调控介电常数的方法，以用于纳米器件和超级电容器。
