Persistent and reversible electrostatic control of doping in graphene/hexagonal boron nitride heterostructures
Persistent and reversible electrostatic control of doping in graphene/hexagonal boron nitride heterostructures
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DOI：
10.1063/1.5127770
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发表时间：
2020-01
影响因子：
3.2
通讯作者：
E. Quezada-López;F. Joucken;H. Chen;A. Lara;J. Davenport;K. Hellier;T. Taniguchi;K. Watanabe;S. Carter;A. P. Ramirez;J. Velasco
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文献类型：
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作者：
E. Quezada-López;F. Joucken;H. Chen;A. Lara;J. Davenport;K. Hellier;T. Taniguchi;K. Watanabe;S. Carter;A. P. Ramirez;J. Velasco
六方氮化硼(HBN)自首次作为石墨烯基场效应晶体管(FET)衬底应用以来，已成为二维材料器件中的重要组成部分。此外，hBN已被证明是缺陷的宿主，这些缺陷可以被操纵来改变相邻2D材料的电子性质。尽管这种缺陷操作已经得到了广泛的应用，但对于缺陷激发及其在石墨烯/hBN FET中的影响还没有得到深入的了解。在这项研究中，我们探索了强电场(∼10V/nm)对石墨烯/hBN FET的影响，发现石墨烯的电荷中性点发生了持久的和可逆的移动。通过增加器件的外加电场和温度，我们发现这种CNP漂移得到了增强。基于这一观点，我们提出了一种基于hBN缺陷的Poole-Frenkel发射来解释这些观察结果的机制。最后，我们发现使用石墨作为后栅可以抑制这种效应，从而防止石墨烯/hBN FET电学性质的意外变化。自从作为石墨烯场效应管(FET)的衬底以来，六方氮化硼(HBN)已经成为二维(2D)材料器件中的重要元件。此外，hBN已被证明是缺陷的宿主，这些缺陷可以被操纵来改变相邻2D材料的电子性质。尽管这种缺陷操作已经得到了广泛的应用，但对于缺陷激发及其在石墨烯/hBN FET中的影响还没有得到深入的了解。在这项研究中，我们探索了强电场(∼10V/nm)对石墨烯/hBN FET的影响，发现石墨烯的电荷中性点发生了持久的和可逆的移动。通过增加器件的外加电场和温度，我们发现这种CNP漂移得到了增强。基于这一观点，我们提出了一种基于hBN缺陷的Poole-Frenkel发射来解释这些观察结果的机制。最后，我们证明了这种效应可以通过使用图形来抑制。
Since its first application as a substrate for graphene field effect transistors (FETs), hexagonal boron nitride (hBN) has become a prominent component in two-dimensional (2D) material devices. In addition, hBN has been shown to host defects that can be manipulated to change the electronic properties of adjacent 2D materials. Despite the wide use of such defect manipulations, no focused efforts have been made to further the understanding of defect excitations and their influence in graphene/hBN FETs. In this study, we explore the effect of high electric fields ( ∼ 10 V / nm ) on graphene/hBN FETs and find that persistent and reversible shifts in graphene's charge neutrality point (CNP) occur. By increasing the applied electric field and temperature of our device, we find that this CNP shift is enhanced. With this insight, we propose a mechanism that explains these observations based on Poole–Frenkel emissions from defects in hBN. Finally, we show that such an effect may be suppressed by using graphite as a backgate, thus preventing unintended changes in the electrical properties of graphene/hBN FETs.Since its first application as a substrate for graphene field effect transistors (FETs), hexagonal boron nitride (hBN) has become a prominent component in two-dimensional (2D) material devices. In addition, hBN has been shown to host defects that can be manipulated to change the electronic properties of adjacent 2D materials. Despite the wide use of such defect manipulations, no focused efforts have been made to further the understanding of defect excitations and their influence in graphene/hBN FETs. In this study, we explore the effect of high electric fields ( ∼ 10 V / nm ) on graphene/hBN FETs and find that persistent and reversible shifts in graphene's charge neutrality point (CNP) occur. By increasing the applied electric field and temperature of our device, we find that this CNP shift is enhanced. With this insight, we propose a mechanism that explains these observations based on Poole–Frenkel emissions from defects in hBN. Finally, we show that such an effect may be suppressed by using graphit...