Ultra-low thermal conductivity and high thermoelectric performance realized in a Cu3SbSe4 based system

Abstract

Cu₃SbSe₄-Based materials were fabricated through Sn-doping and AgSb_0.98Ge_0.02Se₂ incorporation and their thermoelectric properties were investigated in the temperature range from 300 K to 675 K. A remarkable enhancement in thermoelectric performance was obtained, which can be ascribed to the synergistic adjustment of electrical and thermal transport. The introduction of AgSb_0.98Ge_0.02Se₂ nanoparticles strengthened phonon scattering in the composites, resulting in a low thermal conductivity. Simultaneously, a high power factor was maintained. As a result, a maximum figure of merit of 1.23 was obtained at 675 K for the sample Cu₃Sb_0.96Sn_0.04Se₄–3 wt% AgSb_0.98Ge_0.02Se₂, which is one of the highest values ever reported in the Cu₃SbSe₄-based system.