XVII Interstate Conference ''Thermoelectrics and Their Applications -- 2021" (ISCTA 2021 St. Petersburg, September 13-16, 2021)
Effective mass, mobility of charge carriers, and lattice thermal conductivity in nanocomposite thermoelectrics based on bismuth and antimony chalcogenides
Abstract:
In $p$-type thermoelectrics based on bismuth and antimony chalcogenides with a bismuth excess, the effective mass of the density of states $m/m_0$ increases in nanocomposite and nanostructured solid solutions compared with the base material obtained by the direct crystallization method. It is shown that an increase in $m/m_0$ is associated with an increase in the effective scattering parameter $r_{\operatorname{reff}}$ and strengthening of the dependence of the relaxation time on energy, which is typical for topological insulators. The material parameter $\beta$, proportional to the thermoelectric efficiency of ZT, at temperatures below room temperature increases greater in the nanostructured composition than in the nanocomposite with the inclusions of SiO$_2$ due to the growth of $m/m_0$ and a decrease in the lattice thermal conductivity $\kappa_{\mathrm{L}}$. At high temperatures in the range of 300–500 K, the greatest growth in parameter $\beta$ in the base material is associated with higher mobility.
Keywords:bismuth and antimony chalcogenides, nanostructured solid solutions, nanocomposite, effective mass.
Fulltext:
PDF file (282 kB)
