Nano-enhanced thermoelectric materials via melt spinning

Abstract

Melt Spinning has been an attractive method for bulk processing owing to its scalability, fast processing and rapid cooling. It is a promising method to produce bulk nanostructured materials which requires rapid cooling and large scale production at the same time. Melt Spinning technique has been employed to prepare multiphase Sb2Te3 – SnTe in this project. Sb2Te3 was used because it is an established TE material that has a high ZT (≈ 1) and SnTe was used due to its high electrical conductivity and good TE properties. Various compositions ranging from pure SnTe, 80%SnTe – 20%Sb2Te3, 88%SnTe – 12%Sb2Te3, 94%SnTe – 6%Sb2Te3 and pure Sb2Te3 have been prepared using Melt Spinning and were characterized using SEM, XRD, laser flash and ZEM. The resulting ZT has been calculated based on their thermal conductivity, electrical conductivity and Seebeck coefficient. It was found out that 94%SnTe – 6%Sb2Te3 has the highest ZT compared to the rest of multiphase compositions. Nevertheless, the ZT of pure Sb2Te3 obtained was still higher compared to the ZT value 94%SnTe – 6%Sb2Te3. Hence, it showed that there is no enhancement in the TE properties of the multiphase material. A possible reason was due to the formation of SnSb2Te4 besides SnTe and Sb2Te3, leading to bad TE properties.