(BI0.25SB0.75)2Te3 THERMOELECTRIC PELLET CRYSTALLIZED BY HOT ZONE MELTING METHOD TO FIX IN A SEMICONDUCTOR ELECTRIC GENERATOR

Bi2Te3-Sb2Te3 thermoelectric compound with rich side of Sb2Te3 were prepared by the zone melting method and processed under hot pressing method in order to study their thermoelectric properties at different status. (Bi0.25Sb0.75)2Te3 compound is a well known p type material with optimal properties in a module of the thermoelectric semiconductor electric generator. The compound was crystallized then, pulverized as powder. The powder was sintered in a heat up to 350-500 ?C under pressure of 500 MPa (hot pressing). Thermoelectric properties of hot pressed specimens were changed as a function of particle size, pressing, time compressive force and hot pressing temperature. Intrinsic structures were characterized by X-ray diffraction and scanning electron microscopy. The acquired images show homogeneous structures for hot pressed samples. The transport properties of thermoelectric pellets were defined to consider the efficiency. Seebeck coefficient, electrical and thermal conductivities of the pellets are the ruling parameters regarding figure of merit (Z), for the power generator.