Calderon V Sebastian, Ferreira Rafael V, Taneja Deepyanti, Jayanth R T, Zhou Langyan, Ribeiro Ricardo M, Akinwande Deji, Ferreira Paulo J
INL, International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330 Braga, Portugal.
Mechanical Engineering Department and IDMEC, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
Nano Lett. 2021 Dec 22;21(24):10157-10164. doi: 10.1021/acs.nanolett.1c02334. Epub 2021 Nov 30.
In this study, we use differential phase contrast images obtained by scanning transmission electron microscopy combined with computer simulations to map the atomic electrostatic fields of MoS monolayers and investigate the effect of sulfur monovacancies and divancancies on the atomic electric field and total charge distribution. A significant redistribution of the electric field in the regions containing defects is observed, with a progressive decrease in the strength of the projected electric field for each sulfur atom removed from its position. The electric field strength at the sulfur monovacancy sites is reduced by approximately 50% and nearly vanishes at the divacancy sites, where it drops to around 15% of the original value, demonstrating the tendency of these defects to attract positively charged ions or particles. In addition, the absence of the sulfur atoms leads to an inversion in the polarity of the total charge distribution in these regions.
在本研究中，我们使用扫描透射电子显微镜获得的差分相衬图像并结合计算机模拟，来绘制二硫化钼单层的原子静电场，并研究单硫空位和双硫空位对原子电场和总电荷分布的影响。我们观察到含缺陷区域的电场有显著重新分布，从其位置移除的每个硫原子的投影电场强度逐渐降低。单硫空位处的电场强度降低了约50%，在双硫空位处几乎消失，降至原值的15%左右，这表明这些缺陷有吸引带正电离子或粒子的趋势。此外，硫原子的缺失导致这些区域总电荷分布的极性反转。
