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arXiv 1707.02706cond-mat.mtrl-sci
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Sn和V族元素单层中Stone-Wales缺陷的隧穿特性

Tunnelling Characteristics of Stone-Wales Defects in Monolayers of Sn and Group-V Elements

Pooja Jamdagni, Ashok Kumar, Anil Thakur, Ravindra Pandey, P. K. Ahluwalia

摘要:

在多层膜的合成和加工过程中,常常会形成拓扑缺陷,从而严重影响其电子性能。在本文中,我们调查的作用,斯通-威尔士(SW)缺陷在修改的电子性质的单分子膜的Sn和V族元素。计算结果发现锡烯(Sn原子单层)的电子性质强烈依赖于SW缺陷的浓度,当缺陷浓度为2.2 x 10^13 cm^-2时,有缺陷的锡烯的带隙几乎为零(约0.03 eV),当缺陷浓度为3.7 x 10^13 cm^-2时,带隙最大为0.2 eV。相反,SW-缺陷出现诱导导电状态的半导体单层的V族元素。这些导电状态作为电子隧穿的通道,和计算的隧穿特性示出了最高的微分电导的负偏压与不对称的电流-电压特性。在另一方面,最高的微分电导被发现的正偏锡烯。锡烯和V族元素单分子膜的STM形貌模拟图像显示出明显不同的横截面和距离-高度轮廓特征,这些特征可以作为实验中识别IV族和V族元素单分子膜中拓扑缺陷的指纹。

英文摘要:

Topological defects in ultrathin layers are often formed during synthesis and processing, thereby, strongly influencing their electronic properties . In this paper, we investigate the role of Stone-Wales (SW) defects in modifying the electronic properties of the monolayers of Sn and group-V elements. The calculated results find the electronic properties of stanene (monolayer of Sn atoms) to be strongly dependent on the concentration of SW-defects e.g., defective stanene has nearly zero band gap (~ 0.03 eV) for the defect concentration of 2.2 x 10^13 cm^-2 which opens up to 0.2 eV for the defect concentration of 3.7 x 10^13 cm^-2. In contrast, SW-defects appear to induce conduction states in the semiconducting monolayers of group-V elements. These conduction states act as channels for electron tunnelling, and the calculated tunnelling characteristics show the highest differential conductance for the negative bias with the asymmetric current-voltage characteristics. On the other hand, the highest differential conductance was found for the positive bias in stanene. Simulated STM topographical images of stanene and group-V monolayers show distinctly different features in terms of their cross-sectional views and distance-height profiles which can serve as fingerprints to identify the topological defects in the monolayers of group-IV and group-V elements in experiments.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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