The effect of nickel doping on electron and phonon transport in the n-type nanostructured thermoelectric material CoSbS

Abstract

The effect of Ni doping on both electron and phonon transport properties of nanostructured CoSbS has been investigated in this study. We found a more than 2 times increase on figure-of-merit (ZT). The noticeable enhancement is mainly attributed to the optimized carrier concentration, high effective mass and strong electron–phonon scattering upon Ni doping. A ZT of 0.5 was achieved at 873 K together with a power factor of 20 μW cm⁻¹ K⁻² for the Ni doped CoSbS samples. The reduced lattice thermal conductivity via the strong electron–phonon scattering for Ni doped CoSbS samples is confirmed by the quantitative calculation of the various phonon scattering mechanisms according to the Callaway model.