Thermoelectric Properties of CuSe Synthesized by Hydrothermal Method and Densified by SPS Technique.

The aim of the work was to obtain copper (I) selenide CuSe material with excellent thermoelectric properties, synthesized using the hydrothermal method and densified by the spark plasma sintering (SPS) method. Chemical and phase composition studies were carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) methods. Measurements of thermoelectric transport properties, i.e., electrical conductivity, the Seebeck coefficient, and thermal conductivity in the temperature range from 300 to 965 K were carried out. Based on these results, the temperature dependence of the thermoelectric figure of merit as a function of temperature was determined. The obtained, very high parameter (~1.75, = 965 K) is one of the highest obtained so far for undoped CuSe.