SINGLE CRYSTAL BISMUTH TELLURIDE

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Abstract:

Bismuth telluride single crystals were grown by the Czochralski pulling method in a furnace similar to that used by Ainsworth. Bismuth rich and stoichiometric melts led to p-type crystals. Large excesses of Te and doping with Cu2Te led to n-type crystals. Single crystal gwowth was sustained at rates as high as 8.5 cmhr from p-type melts and 0.5 cmhr from n-type melts. Growth rates above 3 cmhr resulted in rectangular cross sections. Those below 1 cmhr resulted in elliptical cross sections similar to those reported by Ainsworth. Typical cross section dimensions were 1.5 x 0.5 cm. Single crystals have been grown up to 22 cm in length. The variation of thermoelectric power with melt composition was observed for compositions near stoichiometry. Normal p-type thermoelectric powers seebeck coefficient ranged from 220 to 260 microvoltsdeg C. Normal n-type thermoelectric powers of -15 to -250 microvoltsdeg C were obtained. X-ray diffraction lines observed agree with the ASTM index to within experimental error. A transmission edge was observed at approximately 0.145 ev. Author

Author(s):
Yang, A. C. ; Shepherd, F. D. Jr.
Author Organization(s):
AIR FORCE CAMBRIDGE RESEARCH LABS L G HANSCOM FIELD MASS
Annotation:
GROWTH OF BI2TE3 CRYSTALS BY THE CZOCHRALSKI METHOD; THERMOELECTRIC ENERGY CONVERSION AS RELATED TO SEMICONDUCTOR RESEARCH.
Pagination:
0036

Security Markings

DOCUMENT & CONTEXTUAL SUMMARY

Distribution:
Approved For Public Release

RECORD

Collection: TR
Identifying Numbers
Report Number(s):
62 362
Project Number(s):
5621
 Subject Terms
Communities of Interest:
Energy and Power Technologies
Descriptor(s):
*INTERMETALLIC COMPOUNDS, *SEMICONDUCTORS, *SINGLE CRYSTALS, *THERMOELECTRICITY, BISMUTH COMPOUNDS, COPPER COMPOUNDS, CRYSTALLIZATION, CRYSTALS, IMPURITIES, MELTING, OPTICS, PHYSICAL PROPERTIES, PREPARATION, ROTATION, TELLURIDES, TEST EQUIPMENT, WAVE PROPAGATION, X RAY PHOTOGRAPHY
Keyword(s):
CRYSTAL PULLING, CZOCHRALSKI METHOD
Report Date:
1962 Sep 01