Effect of a graded in profile on the figure of merit of PbTe

Z. Dashevsky, S. Shusterman, A. Horowitz, M. P. Dariel

Research output: Contribution to journalConference articlepeer-review

6 Scopus citations

Abstract

The present study was aimed at demonstrating the possibility of producing a graded charge carrier concentration in a PbTe crystal by taking advantage of the concentration profile that is set up by the diffusion of In from an external source. Doping by indium generates deep impurity levels lying close to the edge of the conduction band. The Fermi level pinning effect and the electron population of the In impurity levels, which reduces the minority carrier concentration at elevated temperature, significantly improve the thermoelectric behavior of the resulting material. The penetration profiles of In, originating from an external gaseous or liquid source, were determined using Seebeck coefficient measurements in p- and n-type PbTe crystals. In the p-type crystal, the Seebeck coefficient changed sign as the In concentration induced a change from p-type to n-type character. The thermovoltage of a PbTe crystal in which an In concentration profile, generated by In diffusing from a gaseous source had been established, was determined in the 50 to 430°C temperature range. The constant Seebeck coefficient that was observed over the whole temperature range provides the experimental support for the underlying premises of this study.

Original languageEnglish
Pages (from-to)513-517
Number of pages5
JournalMaterials Research Society Symposium - Proceedings
Volume545
StatePublished - 1 Jan 1999
EventProceedings of the 1998 MRS Fall Meeting - The Symposium 'Advanced Catalytic Materials-1998' - Boston, MA, USA
Duration: 30 Nov 19983 Dec 1998

ASJC Scopus subject areas

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

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