Effect of Sn Doping on Surface States of Bi 2 Se 3 Thin Films
Effect of Sn Doping on Surface States of Bi 2 Se 3 Thin Films
复制标题
Sn掺杂对Bi 2 Se 3 薄膜表面态的影响
DOI：
10.1021/acs.jpcc.0c07176
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Mayergoyz, Isaak
中科院分区：
文献类型：
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作者：
Stephen, Gregory M.;Naumov, Ivan;Tyagi, Siddharth;Vail, Owen A.;DeMell, Jennifer E.;Dreyer, Michael;Butera, Robert E.;Hanbicki, Aubrey T.;Taylor, Patrick J.;Mayergoyz, Isaak
Bi2Se_3作为一种被广泛研究的拓扑绝缘体，在低功率电子学和量子计算方面具有巨大的应用潜力。然而，本征掺杂是一个持久的挑战，导致主要是块状导电。在这项工作中，我们使用替位的锡掺杂来控制Bi2Se3薄膜中的费米能级。扫描隧道显微镜(STM)显示，随着掺入更多的锡，局域态密度向狄拉克点移动。密度泛函理论计算解释了扫描隧道显微镜的结果，表明锡在费米能级附近添加了局域化到缺陷位置的金属态，而不干扰狄拉克锥体。电子输运测量表明，尽管体导仍然是主要成分，但锡缺陷增加了体态和表面态之间的分离。
Bi2Se3, widely studied as a topological insulator, has great potential for applications in low-power electronics and quantum computing. Intrinsic doping, however, presents a persistent challenge, leading to predominantly bulk conduction. In this work, we use substitutional Sn dopants to control the Fermi level in Bi2Se3films. Scanning tunneling microscopy (STM) shows a shift in the local density of states toward the Dirac point as more Sn is incorporated. Density functional theory calculations elucidate the STM results, showing that Sn adds metallic states near the Fermi level that are localized to the defect sites while leaving the Dirac cone undisturbed. Electronic transport measurements demonstrate that the Sn defects increase the separation between bulk and surface states, though bulk conduction remains a dominant component.