Electrical Transport Properties of Polycrystalline Monolayer Molybdenum Disulfide
Electrical Transport Properties of Polycrystalline Monolayer Molybdenum Disulfide
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DOI：
10.1021/nn501701a
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发表时间：
2014-08-01
期刊：
影响因子：
17.1
通讯作者：
Lou, Jun
中科院分区：
文献类型：
--
作者：
Najmaei, Sina;Amani, Matin;Lou, Jun
半导体 MoS2 单层材料已显示出许多有前途的电性能，而合成大面积薄膜中不可避免的多晶性使得了解晶界（GB，或二维材料中的线缺陷）等结构缺陷的影响变得至关重要。在这项工作中，我们首先研究了 GBs 在具有不同线缺陷密度的 MoS2 单层电传输特性中的作用。我们揭示了随着线缺陷密度的增加，电气特性会发生系统性退化。进一步研究了两种常见的 MoS2 晶界类型及其具体作用，我们发现只有倾斜晶界对 MoS2 的电性能有相当大的影响。通过使用温度依赖性输运研究检查电子态和无序来源，我们采用无序系统的安德森模型来解释在不同温度条件下观察到的输运行为。我们的结果阐明了 GB 在不同场景中所扮演的角色，并深入了解其潜在的散射机制。
Semiconducting MoS2 monolayers have shown many promising electrical properties, and the inevitable polycrystallinity in synthetic, large-area films renders understanding the effect of structural defects, such as grain boundaries (GBs, or line-defects in two-dimensional materials), essential. In this work, we first examine the role of GBs in the electrical transport properties of MoS2 monolayers with varying line-defect densities. We reveal a systematic degradation of electrical characteristics as the line-defect density increases. The two common MoS2 GB types and their specific roles are further examined, and we find that only tilt GBs have a considerable effect on the MoS2 electrical properties. By examining the electronic states and sources of disorder using temperature-dependent transport studies, we adopt the Anderson model for disordered systems to explain the observed transport behaviors in different temperature regimes. Our results elucidate the roles played by GBs in different scenarios and give insights into their underlying scattering mechanisms.