Monolayers of transition-metal dichalcogenides (TMDs) hold great promise as future nanoelectronic and optoelectronic devices. An essential feature for achieving high device performance is the use of suitable supporting substrates, which can affect the electronic and optical properties of these two-dimensional (2D) materials. Here, we perform many-body GW calculations using the SternheimerGW method to investigate the quasiparticle band structure of monolayer ${\mathrm{MoS}}_2$ subject to an effective dielectric screening model, which is meant to approximately describe substrate polarization in real device applications. We show that, within this model, the dielectric screening has a sizable effect on the quasiparticle band gap; for example, the gap renormalization is as large as 250 meV for ${\mathrm{MoS}}_2$ with model screening corresponding to ${\mathrm{SiO}}_2$. Within the ${\mathrm{G}}_0{\mathrm{W}}_0$ approximation, we also find that the inclusion of the effective screening induces a direct band gap, in contrast to the unscreened monolayer. We also find that the dielectric screening induces an enhancement of the carrier effective masses by as much as 27% for holes, shifts plasmon satellites, and redistributes quasiparticle weight. Our results highlight the importance of the dielectric environment in the design of 2D TMD-based devices.

中文翻译：

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SternheimerGW方法研究单层MoS2的GW带结构及介电环境的影响

作为未来的纳米电子和光电器件，过渡金属二硫化碳（TMD）的单分子层具有广阔的前景。实现高设备性能的基本特征是使用合适的支撑基板，这可能会影响这些二维（2D）材料的电子和光学性能。在这里，我们使用SternheimerGW方法执行多体GW计算，以研究单层的准粒子能带结构${\mathrm{硫化钼}}_{\mathrm{2个}}$受到有效介电筛选模型的约束，该模型旨在大致描述实际设备应用中的基板极化。我们表明，在该模型中，介电屏蔽对准粒子带隙具有相当大的影响；例如，对于${\mathrm{硫化钼}}_{\mathrm{2个}}$ 与对应的模型筛选 ${\mathrm{二氧化硅}}_{\mathrm{2个}}$。内${\mathrm{G}}_0{\mathrm{w\; ^}}_0$近似地，我们还发现，与未筛选的单分子层相比，包含有效筛选的分子会引起直接的带隙。我们还发现，介电筛选可将空穴的载流子有效质量提高多达27％，移动等离激元卫星，并重新分配准粒子重量。我们的结果强调了介电环境在基于2D TMD的设备设计中的重要性。