The variation of the electronic structure normal to 1D defects in quasi-freestanding MoS₂, grown by molecular beam epitaxy, is investigated through high resolution scanning tunneling spectroscopy at 5 K. Strong upward bending of valence and conduction bands toward the line defects is found for the 4|4E mirror twin boundary and island edges but not for the 4|4P mirror twin boundary. Quantized energy levels in the valence band are observed wherever upward band bending takes place. Focusing on the common 4|4E mirror twin boundary, density functional theory calculations give an estimate of its charging, which agrees well with electrostatic modeling. We show that the line charge can also be assessed from the filling of the boundary-localized electronic band, whereby we provide a measurement of the theoretically predicted quantized polarization charge at MoS₂ mirror twin boundaries. These calculations elucidate the origin of band bending and charging at these 1D defects in MoS₂. The 4|4E mirror twin boundary not only impairs charge transport of electrons and holes due to band bending, but holes are additionally subject to a potential barrier, which is inferred from the independence of the quantized energy landscape on either side of the boundary.

中文翻译：

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MoS2中的线缺陷处的带弯曲和价带量化。

准独立MoS _2中垂直于一维缺陷的电子结构的变化通过分子束外延生长的，通过高分辨率扫描隧穿光谱在5 K下进行了研究。对于4 | 4E镜面孪晶边界和岛边缘，对于4 | 4E镜面边界，发现价键和导带朝着线缺陷强烈向上弯曲。 4P镜面双边界。在价带向上弯曲的任何地方都可以观察到价带中的量化能级。集中于常见的4 | 4E镜孪晶边界，密度泛函理论计算给出了其带电估计，这与静电建模非常吻合。我们表明线电荷也可以通过边界局限电子带的填充来评估，从而提供了理论上预测的MoS ₂极化极化电荷的测量镜像双边界。这些计算阐明了MoS ₂中这些一维缺陷处的带弯曲和带电的起源。4 | 4E镜面孪晶边界不仅会由于能带弯曲而削弱电子和空穴的电荷传输，而且还会使空穴受到势垒的影响，这是由边界两侧的量化能量分布的独立性得出的。