Thermoelectric properties of Zn-Sb compound semiconductor

Abstract

The article discusses the results obtained in the study of the thermoelectric properties of the semiconducting Zn-Sb polycrystalline structure obtained by powder technology. Studies show that thermal processing stages and temperature changes significantly affect its thermoelectric properties. At the initial stages of heat treatment, with an increase in temperature, the Seebeck coefficient (α), thermal conductivity (λ) and thermoelectric index (ZT) first decrease, then increase, and decrease again with an increase in temperature. From the fourth stage of heat treatment, all parameters increase with temperature. The research results were explained on the basis of the formation of intergranular boundary areas and its physical properties. The first stage of thermal treatment is the initial stage of ZnSb particle fusion, and the supplied thermal energy Q is not enough for ZnSb particle fusion. In the next stage of heat treatment, the atoms of the crystal lattice, which consists of a broken bond or defect between the pressed particles, are forced together or condensed. As the temperature increases, the phases of the crystal lattice atoms change and their reactivity increases. This leads to the formation of a ZnSb semiconductor with a polycrystalline structure. As the temperature increases, the localized traps with Ein energy level are ionized and electron-hole pairs are formed in the two adjoining boundary areas. Charges created in area A move to area V, which has a relatively low temperature, along the Ein energy levels. As a result, the total λ increases at the same time as the thermal conductivity of these two adjacent areas.