Bismuth telluride
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Bismuth telluride (Bi2Te3) is a grey powder that is a compound of bismuth and tellurium also known as Bismuth(III) telluride. It is a semiconductor which is an efficient thermoelectric material for refrigeration or portable power generation. The CAS registry number is []. The density is 7700 kg.m-3. It has a melting point of 573 C.
The properties relevant to thermoelectric efficiency are:
- a high Seebeck coefficient (voltage per unit temperature difference) Seebeck coefficient of N-type bismuth telluride is -287 μV/°C[1] Seebeck coefficient of P-type Bismuth Telluride is 81μV/K[2]
- a high electrical conductivity, electrical conductivity of N-type bismuth telluride is 3.356 Siemens per meter, which is about 2/3 the electrical conductivity of sea water.[3]
- low thermal conductivity. Thermal conductivity of bismuth telluride is 1.20W/(m*K) giving the compound a thermal insulation value similar to ordinary glass.[4]
[edit] Toxicity
Although generally a low risk compound, it can be toxic; fatal if large doses are ingested. Avoid breathing the dust. A reaction with water may release toxic fumes. Material safety data sheets should be consulted.
[edit] References
- The performance of bismuth telluride thermojunctions, H. J. Goldsmid, A. R. Sheard and D. A. Wright, Br. J. Appl. Phys. vol. 9 pp. 365-370 (1958) DOI:10.1088/0508-3443/9/9/306
[edit] External link
- MSDS at espimetals.com
- Links to external chemical sources
