Accession Number : ADA191346

Title :   Preparation of Improved PbSnTe Thermoelectric Alloys and Evaluation of their Figure of Merit.

Descriptive Note : Final technical rept. 1986-1987,

Corporate Author : UNIVERSITY OF WALES INST OF SCIENCE AND TECHNOLOGY CARDIFF

Personal Author(s) : Rowe, D M

PDF Url : ADA191346

Report Date : Dec 1987

Pagination or Media Count : 27

Abstract : Lead telluride type semiconductors are used in the fabrication of thermoelectric modules currently employed in a number of US military applications. This report covers a programme to produce materials based upon commercially available lead telluride type material (specifically identified as 3P) with improved figures of merit and hence greater thermoelectric conversion efficiency. One way of improving the figure of merit is by reducing the lattice thermal conductivity of the material in order to increase phonon-grain boundary scattering. A realistic model has been developed for PbSnTe and used to investigate the dependence of the lattice thermal conductivity on grain size and level doping. Thermal diffusivity measurements on small gain size compacted 3P material indicate that the reduction in lattice thermal conductivity is more than double that predicted by the theoretical model and is comparable to the reduction reported for silicon germanium alloys. The measured electric power factor values do not appear to decrease with a reduction in grain or size.

Descriptors :   *LEAD COMPOUNDS, *SEMICONDUCTORS, *TELLURIDES, EFFICIENCY, ELECTRIC POWER, FIGURE OF MERIT, GERMANIUM ALLOYS, GRAIN BOUNDARIES, GRAIN SIZE, MATERIALS, MILITARY APPLICATIONS, MODELS, PHONONS, SILICON ALLOYS, THERMAL PROPERTIES, THERMOELECTRIC POWER GENERATION, THERMOELECTRICITY, LEAD ALLOYS, TRANSPORT PROPERTIES, DOPING, DENSITY, TABLES(DATA)

Subject Categories : Electrical and Electronic Equipment
      Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE