POWER-DENSE THERMOELECTRIC MODULE PHASE IV: SOLIDIFICATION OF THERMOELECTRIC MATERIALS UNDER THE INFLUENCE OF ULTRASONIC AGITATION

摘要

A technique is described for preparing fine-grained PbTe, PbTe-SnTe, Bi2Te3 , Bi2Te3-Bi2Se3 , and Bi2Te3-Sb2Te3 by ultrasonic agitation of a solidifying melt. Material prepared by this technique is dense and chemically homogeneous. The electrical properties of optimally doped material have been measured as a function of temperature and compared in most cases with those of material prepared by conventional techniques. The thermoelectric efficiency factors of ultrasonically prepared PbTe and PbTe-SnTe compare very favorably with that of material prepared by other techniques. The ultrasonically prepared Bi2Te3 and Bi2Te3 alloys normally possess lower thermoelectric-efficiency factors ( a2/p ) than material prepared by directional solidification.