Bi1-xSbx alloy thin film and superlattice thermoelectrics

S. Cho*, I. Vurgaftman, A. B. Shick, A. DiVenere, Y. Kim, S. J. Youn, C. A. Hoffman, G. K.L. Wong, A. J. Freeman, J. R. Meyer, J. B. Ketterson

*Corresponding author for this work

Research output: Contribution to journalConference article

Abstract

We have grown Bi1-xSbx alloy thin films on CdTe(111)B over a wide range of Sb concentrations (0≤x≤0.183) using MBE. We have observed several differences with the bulk system. The 3.5 and 5.1% Sb alloys show semiconducting behavior, and the Sb concentration with the maximum bandgap is shifted to a lower Sb concentration, from 15% in bulk to 9%. The power factor S2/ρ (where S is thermoelectric power(TEP) and ρ electrical resistivity) peaks at a significantly higher temperature (250K) than previously reported for the bulk alloy (80K). The magnetotransport properties of Bi1-xSbx thin films (x = 0, 0.09, and 0.16) and Bi/CdTe superlattices have been determined by applying the Quantitative Mobility Spectrum Analysis (QMSA) and multicarrier fitting to the magnetic-field-dependent resistivities and Hall coefficients, using algorithms which account for the strong anisotropy of the mobilities. The calculated S values are in good agreement with experimental results. The structural stability of bulk Bi is studied using the local density linear muffin-tin orbital method. It is shown that the internal displacement changes the Bi electronic structure from a metal to a semimetal, in qualitative agreement with a Jones-Peierls-type transition. The total energy is calculated to have a double well dependence on the internal displacement, and to provide a stabilization of the trigonal phase. We show that an increase of the trigonal shear angle leads to a semimetal-semiconductor transition in Bi.

Original languageEnglish (US)
Pages (from-to)283-294
Number of pages12
JournalMaterials Research Society Symposium - Proceedings
Volume545
StatePublished - Jan 1 1999
EventProceedings of the 1998 MRS Fall Meeting - The Symposium 'Advanced Catalytic Materials-1998' - Boston, MA, USA
Duration: Nov 30 1998Dec 3 1998

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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    Cho, S., Vurgaftman, I., Shick, A. B., DiVenere, A., Kim, Y., Youn, S. J., Hoffman, C. A., Wong, G. K. L., Freeman, A. J., Meyer, J. R., & Ketterson, J. B. (1999). Bi1-xSbx alloy thin film and superlattice thermoelectrics. Materials Research Society Symposium - Proceedings, 545, 283-294.