High thermoelectric performance of polycrystalline In4Se3−δ(CuI)x: synergistic effects of the Se-deficiency and CuI-doping

Abstract

Synergistic effect of Se-deficiency and CuI-doping significantly enhances the thermoelectric figure-of-merit of the n-type polycrystalline In₄Se₃-based materials via improving the power factor. With In₄Se_2.95(CuI)_0.01, ZT = 1.34 at 723 K, the highest value obtained for Pb-free polycrystalline In₄Se₃-based materials to date.