摘要
Background: SnSe 2 is a promising thermoelectric compound. Co, Ni and (Co,Ni) are barrier layer materials. Interfacial reactions are examined since they are very important for the reliability of the thermoelectric modules. Methods: Co/SnSe 2 and (Co, Ni)/SnSe 2 reaction couples are prepared and examined. Their reaction paths are illustrated with the Co-Se-Sn phase equilibria isothermal section and Co-Ni-Se-Sn phase equilibria isothermal tetrahedron, respectively. Significant Findings: At both 500 °C and 300 °C, CoSe and SnSe phases are formed in the Co/SnSe 2 couples. The reaction path is Co/CoSe/SnSe/SnSe 2 . In the (Co,Ni)/SnSe 2 couples reacted at 500 °C, there are three reaction phase regions. The microstructures of these phase regions are very fine. Based on their average compositions, these three phase regions are regarded as Ni 3 Se 2 , Ni 3 SnSe 2 and NiSnSe 2 phases. But the Ni 3 SnSe 2 and NiSnSe 2 phase regions are not single-phase regions and are composed of (Co,Ni)Se+Ni 3 Sn 2 and NiSe+SnSe phases, respectively. It is concluded among the four elements, Ni is the fastest diffusion species, Sn is the slowest, whilst Co and Se have similar diffusion rates. The results indicate Ni is not a suitable barrier layer for SnSe 2 because the interfacial reactions are more significant with more Ni.