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.

Presenters

  • Phoebe Killea

    Kenyon College

Authors

  • Phoebe Killea

    Kenyon College

  • Frank C Peiris

    Physics, Kenyon College, Kenyon College

  • Anthony R. Richardella

    Pennsylvania State University, Materials Research Institute, Pennsylvania State University, Department of Physics and Materials Research Institute, Pennsylvania State University

  • Timothy Pillsbury

    Department of Physics and Materials Research Institute, Pennsylvania State University, Materials Research Institute, Pennsylvania State University, Physics, Pennsylvania State University

  • Nitin Samarth

    Department of Physics and Materials Research Institute, Pennsylvania State University, Physics, Penn State University, Physics, The Pennsylvania State University, Pennsylvania State University, Department of Physics, Pennsylvania State University, Materials Research Institute, Pennsylvania State University, Department of Physics, The Pennsylvania State University, Physics, Pennsylvania State University