Characterization of n-type Bi2Te2.7Se0.3 and p-type Bi0.5Sb1.5Te3 ternary like semiconductors fabricated by shock-waved (explosive) consolidation

Vianett Berenice Munoz Estrada, University of Texas at El Paso

Abstract

Powder mixtures of Bi-Te-Se and Bi-Te-Sb were prepared by explosive consolidation to form ternary like n-type and p-type doped Bi 2Te3 thermoelectric materials. Shock-wave monoliths were compared with their corresponding conventional melt-grown n-type and p-type thermoelectric materials. The elemental powder diameters ranged from 40 μm to 3 μm. Vickers microindentation hardnesses of elemental Bi and Te particles were 0.18 and 0.56 GPa respectively. In contrast, the average of microindentation hardness in the shocked monoliths were 1.15GPa for the n-type and 1.31 GPa for the p-type material; compared to 0.72 and 0.68 GPa for the melt-grown n-type and p-type materials respectively. Elemental powders, powder mixtures, shock-wave consolidated monoliths and conventional melt-grown materials were characterized by X-ray Diffraction, Optical Microscopy, Scanning Electron Microscopy with EDS analysis and Transmission Electron Microscopy. The melt-grown materials had measured thermoelectric parameters considerably in excess of the shock-wave consolidated monoliths. Notable shock microstructures were characterized as deformation twins, while the melt-grown materials contained considerable, fine eutectic microstructures. These microstructures do not appear to be conducive to thermoelectric figure of merit optimization. ^

Subject Area

Engineering, Metallurgy|Engineering, Materials Science

Recommended Citation

Munoz Estrada, Vianett Berenice, "Characterization of n-type Bi2Te2.7Se0.3 and p-type Bi0.5Sb1.5Te3 ternary like semiconductors fabricated by shock-waved (explosive) consolidation" (2007). ETD Collection for University of Texas, El Paso. AAI1452588.
http://digitalcommons.utep.edu/dissertations/AAI1452588

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