2022/12/30 by Szot, M., Dybko, K., Mycielski, A. +4
#FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci)
paper · doi:10.48550/arxiv.2212.14616
The preparation method of thermoelectric PbTe-CdTe semiconductor nanocomposite in the form of a bulk material doped with Bi, I or Na, intended for production the mid-temperature thermoelectric energy generators is presented. The method takes advantage of the extremely low mutual solubility of both semiconductors, resulting from their different crystal structure, and is based on a specifically designed Bridgman growth procedure. It is shown that the formation of zinc-blende crystalline CdTe grains in the rock-salt matrix of thermoelectric PbTe can be forced during the synthesis of a composite by introducing Cd in the form of CdTe compound and choosing the growth temperature above the melting point of PbTe but below the melting point of CdTe. X-ray diffraction and SEM-EDX spectroscopy analyzes as well as basic electric and thermoelectric characterization of the nanocomposite samples containing 2, 5 and 10 at. % of Cd showed that using proposed growth procedure, it is possible to obtain both n-type (Bi- or I-doped) and p-type (Na-doped) material with carrier concentration of 1÷5 x 10\19 cm\-3 and uniformly distributed CdTe grains with a diameter of the order of 100 nm.