Thickness-dependent magnetotransport properties and terahertz response of topological insulator Bi2Te3thin films

Phuoc Huu Le, Po-Tsun Liu, Chih-Wei Luo*, Jiunn-Yuan Lin, Kaung-Hsiung Wu

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

20 Scopus citations

Abstract

We report the thickness (d) dependence of structural, morphological, magneto-transport properties as well as terahertz (THz) response in the 0.25–2.25 THz range of topological insulator Bi2Te3thin films grown by pulsed laser deposition (PLD). The Bi2Te3films exhibit a highly c-axis orientation (textured films) and two Raman-active modes of E2 gat 102.5 cm−1and A2 1gat 134.8 cm−1. The films obtain relatively low carrier concentration between 2.0 × 1019and 4.4 × 1019 cm−3. The films present two-dimensional weak (2D WAL) antilocalization magnetoresistance in a low magnetic field (B) and the 2D WAL shows thickness dependence, suggesting the presence of topological surface states (TSS). The THz transmittance increases owing to increased resistivity (associated with a decreased carrier concentration) when film thickness decreases from 152 to 16 QL. The complex conductance is well described by the Drude-Lorentz model with three components of the Drude surface, Drude bulk, and phonon. The Drude spectral weight (SW) of the surface is dominant and independent of the thickness. Besides, the Drude SW of the bulk and phonon SW linearly increase with increasing thickness.

Original languageEnglish
Pages (from-to)972-979
Number of pages8
JournalJournal of Alloys and Compounds
Volume692
DOIs
StatePublished - 25 Jan 2017

Keywords

  • Topological insulator
  • Bismuth telluride
  • Weak antilocalization
  • Terahertz spectroscopy
  • Pulsed laser deposition
  • PULSED-LASER DEPOSITION

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