Optical Properties of MBE-grown (Bi 1-x Sb x ) 2 Te 3 Thin Films
POSTER
Abstract
Spectroscopic ellipsometry was used to determine the dielectric functions of a series of (Bi1-xSbx)2Te3 thin films. The films were grown using molecular beam epitaxy and were deposited on InP substrates. X-ray diffraction, XPS and AFM experiments indicated that the films were of high-quality. Ellipsometry measurements were obtained in the spectral range between 0.05 eV and 6 eV. A standard inversion technique was used to model the ellipsometry spectra, which produced the dielectric functions of each of (Bi1-xSbx)2Te3 thin films. By representing the dielectric function with Kramers-Kronig-consistent oscillators, the fundamental band gap and the higher order transitions of these films were obtained. A Drude oscillator, which represents the absorption of free carriers, was needed to model some films.
*
The work at Kenyon is funded by DMR-1609245 and the work at Penn State is funded by DMR-1539916
Presenters
-
Phoebe Killea
- Kenyon College