Enhanced thermoelectric performance via carrier energy filtering effect in β-Zn4Sb3 alloy bulk embedded with (Bi2Te3)0.2(Sb2Te3)0.8

Abstract

In Pb-free β-Zn4Sb3 based composites incorporated with (Bi2Te3)0.2(Sb2Te3)0.8, we concurrently realize ∼30% increase in thermoelectric power factor through an energy filtering effect caused by carrier scattering at interface barriers, and ∼15% reduction in thermal conductivity due to interface scattering, allowing the figure of merit to reach 1.1 at 648 K in the composite system with 1 vol. % of (Bi2Te3)0.2(Sb2Te3)0.8.