Enhancement in thermoelectric properties of FeSb2 by Sb site deficiency

• Introduction of point defects (in the form of Sb site deficiency) for improving the thermoelectric properties of FeSb2.
• A Sb deficiency to the tune of 20% leads to an enhancement in the values of power factor (S2σ) by a factor of 13 at 35 K.
• A Sb deficiency to the tune of 20% leads to the suppression of cumulative thermal conductivity (κ) by a factor of 4 at 35 K.
• Our results provide ample motivation for exploring the role of Sb site deficiency in single crystals and hot-pressed polycrystalline samples of FeSb2.

We report a strategy based on introduction of point defects for improving the thermoelectric properties of FeSb2, a promising candidate for low temperature applications. Introduction of Sb deficiency to the tune of 20% leads to enhancement in the values of electrical conductivity (σ) and Seebeck coefficient (S) accompanied with a concomitant suppression in lattice thermal conductivity (κlat) values in samples prepared using conventional solid state reaction route. These observations in polycrystalline FeSb2-x provides ample motivation for a dedicated exploration of thermoelectric behavior of the corresponding single crystalline as well as hot-pressed polycrystalline counterparts.

A strategy based on the introduction of Sb site deficiency in FeSb2−x for co-optimization of electronic (le) and phononic (lph) mean free paths for improving thermoelectric behavior.Figure optionsDownload as PowerPoint slide