Enhanced thermoelectric performance of CoSbS0.85Se0.15 by point defect

In this study, we report the effect of Zn doping on the thermoelectric properties of Co1−x Zn x SbS0.85Se0.15 solid solutions (x = 0, 0.02, 0.05, 0.08). The results show the dimensionless figure of merit (zT) increases from 0.17 to 0.34 at 875 K for Co0.95Zn0.05SbS0.85Se0.15 sample, due to the noticeable decrease in the lattice thermal conductivity by introducing point defect, which is further confirmed by an analysis based on the Debye–Callaway–Klemens model. Meanwhile, the thermoelectric power factor is maintained at high temperatures. This work highlights the important role of point defect in improving the thermoelectric performance of CoSbS-based compounds.