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arXiv 1404.1934cond-mat.mes-hallcond-mat.mtrl-sci
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点缺陷对MoS2和WS2光学和输运性质的影响

Effect of Point Defects on the Optical and Transport Properties of MoS2 and WS2

S. Yuan, R. Roldán, M. I. Katsnelson, F. Guinea

摘要:

晶体结构中的缺陷,例如点缺陷,可以强烈地改变材料的光学和输运性质。在这里,我们研究了点缺陷对半导体过渡金属二硫族化合物单层的光学和直流电导率的影响,其形式为$M$ S $_2$,其中$M$ = Mo或W。电子结构被认为是在一个六带紧束缚模型,它占的相关组合的$d$轨道的金属$M$和$p$轨道的硫属元素$S$。我们使用Kubo公式计算具有不同无序分布的样品的电导率。我们发现,$M$和/或S缺陷创建中间的间隙状态,本地化载流子周围的缺陷,并修改材料的光学和输运性质,与最近的实验一致。此外,我们的结果表明,与MoS $_2$相比,$p$掺杂的WS $_2$具有高得多的迁移率。

英文摘要:

Imperfections in the crystal structure, such as point defects, can strongly modify the optical and transport properties of materials. Here, we study the effect of point defects on the optical and DC conductivities of single layers of semiconducting transition metal dichalcogenides with the form $M$S$_2$, where $M$=Mo or W. The electronic structure is considered within a six bands tight-binding model, which accounts for the relevant combination of $d$ orbitals of the metal $M$ and $p$ orbitals of the chalcogen $S$. We use the Kubo formula for the calculation of the conductivity in samples with different distributions of disorder. We find that $M$ and/or S defects create mid-gap states that localize charge carriers around the defects and which modify the optical and transport properties of the material, in agreement with recent experiments. Furthermore, our results indicate a much higher mobility for $p$-doped WS$_2$ in comparison to MoS$_2$.

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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