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arXiv 2005.07466cond-mat.mes-hall
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二维WS $_2$中的替代点缺陷如何引起电荷局域化、自旋轨道分裂和应变

How Substitutional Point Defects in Two-Dimensional WS$_2$ Induce Charge Localization, Spin-Orbit Splitting, and Strain

Bruno Schuler, Jun-Ho Lee, Christoph Kastl, Katherine A. Cochrane, Christopher T. Chen, Sivan Refaely-Abramson, Shengjun Yuan, Edo van Veen, Rafael Roldán, Nich… 展开作者

Bruno Schuler, Jun-Ho Lee, Christoph Kastl, Katherine A. Cochrane, Christopher T. Chen, Sivan Refaely-Abramson, Shengjun Yuan, Edo van Veen, Rafael Roldán, Nicholas J. Borys, Roland J. Koch, Shaul Aloni, Adam M. Schwartzberg, D. Frank Ogletree, Jeffrey B. Neaton, Alexander Weber-Bargioni

摘要:

半导体材料中杂质浓度的控制对器件技术至关重要。由于其固有的限制,二维半导体如过渡金属二硫属化物(TMD)的性质比传统的体材料对缺陷更敏感。TMD的技术采用取决于有害缺陷的减轻和功能性外来原子的引导并入。杂质控制的第一步是识别缺陷并评估其电子特性。在这里,我们提出了一个全面的研究单层二硫化钨(WS $_2$)生长的化学气相沉积(CVD),使用扫描隧道显微镜/光谱,CO-针尖非接触原子力显微镜,开尔文探针力光谱,密度泛函理论,和紧束缚计算的点缺陷。我们观察到四种不同的替代缺陷:铬(Cr $_{\text{W}}$)和钼(Mo $_{\text{W}}$)在钨网站,氧在硫网站在底层和顶层(O $_{\text{S}}$顶部/底部),以及两个带负电荷的缺陷(CD)。它们的电子指纹明确地证实了缺陷分配,并揭示了间隙缺陷状态的存在或不存在。电荷局域化的重要作用,自旋-轨道耦合,和应变的形成深缺陷状态观察到的替代缺陷在WS $_2$在这里报道将指导未来的工作目标缺陷工程和掺杂的TMD。

英文摘要:

Control of impurity concentrations in semiconducting materials is essential to device technology. Because of their intrinsic confinement, the properties of two-dimensional semiconductors such as transition metal dichalcogenides (TMDs) are more sensitive to defects than traditional bulk materials. The technological adoption of TMDs is dependent on the mitigation of deleterious defects and guided incorporation of functional foreign atoms. The first step towards impurity control is the identification of defects and assessment of their electronic properties. Here, we present a comprehensive study of point defects in monolayer tungsten disulfide (WS$_2$) grown by chemical vapor deposition (CVD) using scanning tunneling microscopy/spectroscopy, CO-tip noncontact atomic force microscopy, Kelvin probe force spectroscopy, density functional theory, and tight-binding calculations. We observe four different substitutional defects: chromium (Cr$_{\text{W}}$) and molybdenum (Mo$_{\text{W}}$) at a tungsten site, oxygen at sulfur sites in both bottom and top layers (O$_{\text{S}}$ top/bottom), as well as two negatively charged defects (CDs). Their electronic fingerprints unambiguously corroborate the defect assignment and reveal the presence or absence of in-gap defect states. The important role of charge localization, spin-orbit coupling, and strain for the formation of deep defect states observed at substitutional defects in WS$_2$ as reported here will guide future efforts of targeted defect engineering and doping of TMDs.

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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