Anisotropic Terahertz Emission from Bi2Se3 Thin Films with Inclined Crystal Planes

Sun Young Hamh, Soon Hee Park, Jeongwoo Han, Jeong Heum Jeon, Se-Jong Kahng, Sung Kim, Suk Ho Choi, Namrata Bansal, Seongshik Oh, Joonbum Park, Jun Sung Kim, Jae Myung Kim, Do Young Noh, Jong Seok Lee

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

We investigate the surface states of topological insulator (TI) Bi2Se3 thin films grown on Si nanocrystals and Al2O3 substrates by using terahertz (THz) emission spectroscopy. Compared to bulk crystalline Bi2Te2Se, film TIs exhibit distinct behaviors in the phase and amplitude of emitted THz radiation. In particular, Bi2Se3 grown on Al2O3 shows an anisotropic response with a strong modulation of the THz signal in its phase. From x-ray diffraction, we find that the crystal plane of the Bi2Se3 films is inclined with respect to the plane of the Al2O3 substrate by about 0.27°. This structural anisotropy affects the dynamics of photocarriers and hence leads to the observed anisotropic response in the THz emission. Such relevance demonstrates that THz emission spectroscopy can be a sensitive tool to investigate the fine details of the surface crystallography and electrostatics of thin film TIs.

Original languageEnglish
Article number489
Pages (from-to)1-6
Number of pages6
JournalNanoscale Research Letters
Volume10
Issue number1
DOIs
Publication statusPublished - 2015 Dec 1

Fingerprint

Terahertz spectroscopy
Emission spectroscopy
Thin films
Crystals
Crystallography
Surface states
Substrates
thin films
Nanocrystals
crystals
Electrostatics
Anisotropy
Diffraction
Modulation
Crystalline materials
Radiation
X rays
spectroscopy
crystallography
nanocrystals

Keywords

  • BiSe
  • Terahertz emission
  • Thin film
  • Topological insulator

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics

Cite this

Anisotropic Terahertz Emission from Bi2Se3 Thin Films with Inclined Crystal Planes. / Hamh, Sun Young; Park, Soon Hee; Han, Jeongwoo; Jeon, Jeong Heum; Kahng, Se-Jong; Kim, Sung; Choi, Suk Ho; Bansal, Namrata; Oh, Seongshik; Park, Joonbum; Kim, Jun Sung; Kim, Jae Myung; Noh, Do Young; Lee, Jong Seok.

In: Nanoscale Research Letters, Vol. 10, No. 1, 489, 01.12.2015, p. 1-6.

Research output: Contribution to journalArticle

Hamh, SY, Park, SH, Han, J, Jeon, JH, Kahng, S-J, Kim, S, Choi, SH, Bansal, N, Oh, S, Park, J, Kim, JS, Kim, JM, Noh, DY & Lee, JS 2015, 'Anisotropic Terahertz Emission from Bi2Se3 Thin Films with Inclined Crystal Planes', Nanoscale Research Letters, vol. 10, no. 1, 489, pp. 1-6. https://doi.org/10.1186/s11671-015-1190-y
Hamh, Sun Young ; Park, Soon Hee ; Han, Jeongwoo ; Jeon, Jeong Heum ; Kahng, Se-Jong ; Kim, Sung ; Choi, Suk Ho ; Bansal, Namrata ; Oh, Seongshik ; Park, Joonbum ; Kim, Jun Sung ; Kim, Jae Myung ; Noh, Do Young ; Lee, Jong Seok. / Anisotropic Terahertz Emission from Bi2Se3 Thin Films with Inclined Crystal Planes. In: Nanoscale Research Letters. 2015 ; Vol. 10, No. 1. pp. 1-6.
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