テルル化蒼鉛による熱電冷却

その5: 熱電物質

抄録

For the purpose of obtaining superior thermoelectric materials, purification of Bi, Te and Bi₂Te₃ has been carried out.
Bismuth is purified by the method of alkali-treatment and zone melting in removing Cu, Ag and Pb.
For the purification of tellurium, vacuum distillation is very efficient to remove Cu, Ag and Pb.
Measured thermoelectric power a and resistivity of purified Bi₂Te₃ were α=235μV•deg^-1, and p=1.16×10^-3Ω•cm respectively.
The influence of addictive impurities on Bi₂Te₃ is examined. Tl, Li, Pb and Cd etc. are p-type and Cu, Ag, Se, Te, halogen and metal-halides etc. are n-type impurities.
The thermoelectric properties of PbTe, Sb₂Te₃, Bi₂Te₃-Sb₂Te₃ and Bi₂Te₃-Bi₂Se₃ solid solution are examined. The result shows that the solid solution of isomorphous compounds is suitable for the thermoelectric material.
By the use of (Bi-Sb)₂Te₃ p-type element and Bi₂(Te-Se)₃ n-type element thermojunctions, the temperature drop of 71.3 deg was attained with a temperature of hot junction of 30°C.