Simultaneous enhancement in thermoelectric power factor and phonon blocking in hierarchical nanostructured β-Zn4Sb3-Cu3SbSe4

Abstract

In Pb and Te-free β-Zn4Sb3 based composites incorporated with nanophase Cu3SbSe4 (∼200 nm), we concurrently realize ∼30% increase in thermoelectric power factor (PF) through an energy filtering effect caused by carrier scattering at interface barriers, and around twofold reduction in lattice thermal conductivity due to interface scattering allowing the figure of merit (ZT) to reach 1.37 at 648 K in the composite system with 5 vol. % of Cu3SbSe4. Present results demonstrate that simultaneous enhancement of PF and phonon blocking can be achieved via proper design of a material-system and its microstructures, resulting in large increase in ZT of a material-system.