| The thermoelectric materials of SiGe is one kind of superia materials in hightemperature. The ZT of single crystal of SiGe can reach 0.65.It's one kind potentialthermoelectric materials and have been put into practice .Since 1977,the SiGe alloywas adopted in a ASTRO to generate electricity, it has completely replaced thematerials of PbTe. But the ZT figure is still not large enough.This paper have reviewed and detailed the thermoelectricity, the history ofthermoelectric materials. The studies in existence showed that the solid solutionswhich based with Si80Ge20 and doped with other elements are the best thermoelectricsemiconductors working at high-temperature at present.The p-type Si80Ge20 thermoelectric semiconductor alloys were prepared bypowder metallurgy method and spark plasma sintering. The result showed thatbecause of Si and Ge elements are easily oxidated in high temperature in theprocess of melting and sinter which influenced the thermoelectric properties ofsamples. Ar gas was filled when melting the alloys and used to lower sintertemperature. The melting temperature of Si80Ge20 based thermoelectric material is1400℃. The best sinter temperature is 1250℃. The melting temperature of p-typeSi80Ge20 based thermoelectric material is 1400℃, the best sinter temperature is1125℃.The element compound of p-type Si80Ge20Bx based thermoelectric material solidsolutions were researched. The solid solutions with different x were prepared andtheir thermoelectric properties were compared. The result showed that the bestp-type alloys can be got when x=1.2 The ZT is 0.87, 29.86％larger than the reported0.67.The sample of B and inertia Si3N4 nano-particles dopants added in Si80Ge20 wasresearched. The resistivity is about 6 times comparing with Si80Ge20B1, whileSeebeck coefficient is enhanced slightly and heat conductance decrease from 550K to1000K The ZT is about 0.15. The sample Al dopant added in Si80Ge20 was researched. By comparing withSi80Ge20B1,reveal that resistivity improve about 10 times, while Seebeck coefficientis enhanced 40％and heat conductance decrease obviously, about 1/6 comparing toSi80Ge20B1. The ZT is about 0.024.The SEM micrographs show that the appearance of samples in different dopantsshow layer structure The material is compact, and the grain is even, being propitiousto decrease the resistivity.
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