Realizing high thermoelectric performance in Te nanocomposite through Sb2Te3 incorporation

The rational design and fabrication of nanostructures has become a fashionable strategy for pursing high thermoelectric performance in solid-state materials. Here we report nanostructured Te-Sb2Te3 composites with significantly enhanced thermoelectric performance through a scalable bottom-up method followed by a rapid sintering process. The power factor along with the carrier concentration could be significantly enhanced by increasing the number of point defects of Sb'(Te). Meanwhile, a great number of boundaries and hetero-interfaces between the Te and Sb2Te3 nanoparticles could play an important role in blocking phonons, resulting in the evident suppression of lattice thermal conductivity. Ultimately, a highest zT value close to 1.0 could be achieved at 623 K in samples with components of 2.6 mol% Sb2Te3 and 97.4 mol% Te. Such a peak zT value is comparable to that of doped Te materials synthesized by the conventional solid-state reaction process. This work reveals that high thermoelectric performance could be realized in an intentionally designed nanocomposite by synergistically improving the power factor and suppressing the lattice thermal conductivity.