Jump to main content
Jump to site search

Issue 10, 2013
Previous Article Next Article

Metal–insulator transition in variably doped (Bi1−xSbx)2Se3 nanosheets

Author affiliations

Abstract

Topological insulators are novel quantum materials with metallic surface transport but insulating bulk behavior. Often, topological insulators are dominated by bulk contributions due to defect induced bulk carriers, making it difficult to isolate the more interesting surface transport characteristics. Here, we report the synthesis and characterization of nanosheets of a topological insulator Bi2Se3 with variable Sb-doping levels to control the electron carrier density and surface transport behavior. (Bi1−xSbx)2Se3 thin films of thickness less than 10 nm are prepared by epitaxial growth on mica substrates in a vapor transport setup. The introduction of Sb in Bi2Se3 effectively suppresses the room temperature electron density from ∼4 × 1013 cm−2 in pure Bi2Se3 (x = 0) to ∼2 × 1012 cm−2 in (Bi1−xSbx)2Se3 at x ∼ 0.15, while maintaining the metallic transport behavior. At x ≳ ∼0.20, a metal–insulator transition (MIT) is observed, indicating that the system has transformed into an insulator in which the metallic surface conduction is blocked. In agreement with the observed MIT, Raman spectroscopy reveals the emergence of vibrational modes arising from Sb–Sb and Sb–Se bonds at high Sb concentrations, confirming the appearance of the Sb2Se3 crystal structure in the sample. These results suggest that nanostructured chalcogenide films with controlled doping can be a tunable platform for fundamental studies and electronic applications of topological insulator systems.

Graphical abstract: Metal–insulator transition in variably doped (Bi1−xSbx)2Se3 nanosheets

Back to tab navigation

Supplementary files

Article information


Submitted
06 Mar 2013
Accepted
11 Mar 2013
First published
15 Mar 2013

Nanoscale, 2013,5, 4337-4343
Article type
Paper

Metal–insulator transition in variably doped (Bi1−xSbx)2Se3 nanosheets

C. H. Lee, R. He, Z. Wang, R. L. J. Qiu, A. Kumar, C. Delaney, B. Beck, T. E. Kidd, C. C. Chancey, R. M. Sankaran and X. P. A. Gao, Nanoscale, 2013, 5, 4337 DOI: 10.1039/C3NR01155K

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.


Social activity

Search articles by author

Spotlight

Advertisements