Robust Surface Doping of Bi2Se3 by Rubidium Intercalation

被引：69

作者：

Bianchi, Marco ^{[1
]}

Hatch, Richard C. ^{[1
]}

Li, Zheshen ^{[1
]}

Hofmann, Philip ^{[1
]}

Song, Fei ^{[2
,3
]}

Mi, Jianli ^{[4
]}

Iversen, Bo B. ^{[4
]}

Abd El-Fattah, Zakaria M. ^{[5
,6
]}

Loeptien, Peter ^{[7
]}

Zhou, Lihui ^{[7
]}

Khajetoorians, Alexander A. ^{[7
]}

Wiebe, Jens ^{[7
]}

Wiesendanger, Roland ^{[7
]}

Wells, Justin W. ^{[3
,8
]}

机构：

[1] Aarhus Univ, Dept Phys & Astron, Interdisciplinary Nanosci Ctr, DK-8000 Aarhus C, Denmark

[2] Univ Groningen, Zernike Inst Adv Mat, NL-9747 AG Groningen, Netherlands

[3] Norwegian Univ Sci & Technol NTNU, Dept Phys, Trondheim, Norway

[4] Aarhus Univ, Ctr Mat Crystallog, Dept Chem, Interdisciplinary Nanosci Ctr, DK-8000 Aarhus C, Denmark

[5] Ctr Fis Mat CSIC UPV EHU Mat Phys Ctr, San Sebastian 20018, Spain

[6] DIPC, San Sebastian 20018, Spain

[7] Univ Hamburg, Inst Appl Phys, D-20355 Hamburg, Germany

[8] Lund Univ, MAX Lab 4, S-22100 Lund, Sweden

来源：

ACS NANO | 2012年 / 6卷 / 08期

基金：

欧洲研究理事会;

关键词：

topological Insulators; Bi2Se3; quantum well states; intercalation; alkali atoms;

D O I：

10.1021/nn3021822

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Rubidium adsorption on the surface of the topological insulator Bi2Se3 is found to induce a strong downward band bending, leading to the appearance of a quantum-confined two-dimensional electron gas state (2DEG) in the conduction band. The 2DEG shows a strong Rashba-type spin orbit splitting, and it has previously been pointed out that this has relevance to nanoscale spintronics devices. The adsorption of Rb atoms, on the other hand, renders the surface very reactive, and exposure to oxygen leads to a rapid degrading of the 2DEG. We show that intercalating the Rb atoms, presumably into the van der Waals gaps in the quintuple layer structure of Bi2Se3, drastically reduces the surface reactivity while not affecting the promising electronic structure. The intercalation process is observed above room temperature and accelerated with increasing initial Rb coverage, an effect that is ascribed to the Coulomb interaction between the charged Rb ions. Coulomb repulsion is also thought to be responsible for a uniform distribution of Rb on the surface.

引用

页码：7009 / 7015

页数：7

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