Enhanced thermoelectric performance of stibium and bismuth co-doped SnTe via melt spinning

Abstract

In this work, the thermoelectric (TE) performance of [Formula: see text]-type SnTe based on melt spinning (MS) technology is comprehensively researched. Elements of Sb and Bi are introduced to significantly improve the electrical transport properties. Along with the fine grains, SnTe-based ribbons can be obtained in a short time by MS method. It indicates that the MS technology improves the sample preparation efficiency and reduces the lattice thermal conductivity. The melt-spun one reveals that the lowest lattice thermal conductivity of Sn[Formula: see text]Sb[Formula: see text]Bi[Formula: see text]Te is 0.87 W m[Formula: see text]K[Formula: see text]at 323 K. To optimize the ZT (where [Formula: see text] is the figure of merit and [Formula: see text] is Kelvin temperature) of SnTe, Sb and Bi are codoped in SnTe matrix, as a result of the enhancement of the power factor (PF) value and decreasing the thermal conductivity and electronic thermal conductivity simultaneously. Finally, the highest ZT of 1.01 at 823 K and an average ZT of 0.57 is obtained over a broad temperature range from 323 K to 823 K in Sn[Formula: see text]Sb[Formula: see text]Bi[Formula: see text]Te. It is worth noting that the remarkable improvement on the TE performance of pristine SnTe sample is achieved, with the highest ZT of 0.55 at 823 K and an average ZT of 0.18. It shows the potential for following research on the performance of lead-free SnTe-based TE materials.