Absorption edge, urbach tail, and electron-phonon interactions in topological insulator Bi2Se3 and band insulator (Bi0.89In0.11)2Se3

Authors :: Shengqiang Zhou
Gunther Springholz
Harald Schneider
Yunyouyou Xia
Gang Li
S. Wimmer
Alexej Pashkin
Jiajun Zhu
Manfred Helm
Source :: Applied Physics Letters. 114:162105
Publication Year :: 2019
Publisher :: AIP Publishing, 2019.
Abstract: We employ infrared transmission spectroscopy to explore the temperature-dependent absorption edge and electron-phonon (e-ph) interaction in topological insulator Bi2Se3 and band insulator (Bi0.89In0.11)2Se3 films. Upon heating from 5 K to 300 K, the absorption edge shifts from 262 to 249 meV for Bi2Se3 and from 367 to 343 meV for (Bi0.89In0.11)2Se3. By analyzing the temperature dependence of the Urbach tail, the significant role of Raman-active phonon mode E g 2 in e-ph interaction is identified, which agrees well with the ab initio calculation.

Subjects :: 010302 applied physics
Materials science
Physics and Astronomy (miscellaneous)
Condensed matter physics
Phonon
Ab initio
Infrared spectroscopy
Insulator (electricity)
02 engineering and technology
021001 nanoscience & nanotechnology
01 natural sciences
Absorption edge
Ab initio quantum chemistry methods
Topological insulator
0103 physical sciences
0210 nano-technology
Spectroscopy

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