Robust Direct Bandgap Characteristics of One- and Two-Dimensional ReS2.
Robust Direct Bandgap Characteristics of One- and Two-Dimensional ReS2.
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DOI：
10.1038/srep13783
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发表时间：
2015-09-08
影响因子：
4.6
通讯作者：
Zhang YW
中科院分区：
文献类型：
--
作者：
Yu ZG;Cai Y;Zhang YW
二维（2D）过渡金属二硫属化物（TMD），最值得注意的是，MoS2和WS2，由于其相当大的和直接的带隙特性而引起了极大的关注。虽然已经报道了几种有趣的基于MoS2和WS2的光电器件，但它们的可加工性和再现性受到限制，因为它们的电性能强烈依赖于层的数量、应变和样品尺寸。非常需要具有鲁棒的直接带隙TMD，其对这些因素不敏感。在这项工作中，使用密度泛函理论，我们探讨了层数，应变和带宽度的影响ReS2，在TMD家族的新成员的电子性质。计算结果表明，对于单层ReS2，其带隙的性质（直接与间接）和大小是不敏感的应变。重要的是，预测的带隙和电荷载流子迁移率几乎与层数无关。此外，ReS2纳米带的直接带隙仅弱依赖于它们的宽度。这些强大的特性强烈表明，ReS2在光电纳米器件中具有巨大的应用潜力。
Two-dimensional (2D) transition-metal dichalcogenides (TMDs), most notably, MoS2 and WS2, have attracted significant attention due to their sizable and direct bandgap characteristics. Although several interesting MoS2 and WS2-based optoelectronic devices have been reported, their processability and reproducibility are limited since their electrical properties are strongly dependent of the number of layers, strain and sample sizes. It is highly desirable to have a robust direct bandgap TMD, which is insensitive to those factors. In this work, using density functional theory, we explore the effects of layer number, strain and ribbon width on the electronic properties of ReS2, a new member in the TMD family. The calculation results reveal that for monolayer ReS2, the nature (direct versus indirect) and magnitude of its bandgap are insensitive to strain. Importantly, the predicted bandgap and also charge carrier mobilities are nearly independent of the number of layers. In addition, the direct bandgap of ReS2 nanoribbons is only weakly dependent on their width. These robust characteristics strongly suggest that ReS2 has great potential for applications in optoelectronic nanodevices.