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, Arthur J Freeman, J. R. Meyer, J. B. Ketterson

Research output: Chapter in Book/Report/Conference proceedingChapter

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
Title of host publicationMaterials Research Society Symposium - Proceedings
PublisherMaterials Research Society
Pages283-294
Number of pages12
Volume545
Publication statusPublished - 1999
EventProceedings of the 1998 MRS Fall Meeting - The Symposium 'Advanced Catalytic Materials-1998' - Boston, MA, USA
Duration: Nov 30 1998Dec 3 1998

Other

OtherProceedings of the 1998 MRS Fall Meeting - The Symposium 'Advanced Catalytic Materials-1998'
CityBoston, MA, USA
Period11/30/9812/3/98

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials

Cite this

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. In Materials Research Society Symposium - Proceedings (Vol. 545, pp. 283-294). Materials Research Society.