Simultaneous improvement in electrical and thermal properties of interface-engineered BiSbTe nanostructured thermoelectric materials

Abstract

Over the past decade, nanostructuring has become the core of thermoelectric (TE) material research because it creates numerous internal interfaces that provide an effective way to tune the electrical and/or thermal properties of TE materials. Herein, we report a synthesis of interface-engineered BiSbTe nanostructured TE materials by introducing chemically synthesized molecular Te-n(2-) polyanions into BiSbTe particles, from which BiSbTe nanostructured materials with high-density Te interfacial layers are prepared in thin films and sintered pellets. These Te layers form the contact potential well at the BiSbTe-Te junction to realize energy dependent carrier scattering and scatter phonons effectively, thus resulting in simultaneous improvement in the electrical and thermal properties to increase the ZT value well above 1.3 +/- 0.14 that is increased by 40% compared to bulk BiSbTe. The findings of current study can open up new chemical design spaces for interface-engineered electronic and TE materials.