Raman spectroscopy of epitaxial topological insulator Bi2Te3 thin films on GaN substrates
Journal article, 2015
Bi2Te3 has drawn great attention in recent years as both a topological insulator and the best thermoelectric material at room temperature. We report on Raman spectroscopic study on Bi2Te3 thin films with thicknesses of 20-50 nm grown on GaN by molecular beam epitaxy. All the four classical optical phonon modes are clearly revealed for the first time in ex situ Raman for epitaxial Bi2Te3. Unusual and infrared-active vibration modes are also observed and analyzed. In the resonant Raman measurements, abnormal enhancement and suppression of different modes are studied. The interface modes caused by a large density of domain boundaries formed during coalescence of crystal islands with different lattice orientations and the Frohlich electron-phonon interaction are found to play significant roles during the Raman scattering processes.
Raman spectroscopy
resonant Raman scattering
Bi2Te3
Topological insulator
domain boundaries
electron-phonon interaction
Author
H. Xu
Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences
Chinese Academy of Sciences
Y. X. Song
Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences
Q. Gong
Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences
W. W. Pan
Chinese Academy of Sciences
Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences
X. Y. Wu
Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences
Chinese Academy of Sciences
Shu Min Wang
Chalmers, Microtechnology and Nanoscience (MC2), Photonics
Modern Physics Letters B
0217-9849 (ISSN)
Vol. 29 15Subject Categories (SSIF 2011)
Nano Technology
DOI
10.1142/s021798491550075x