Abstract Scope |
Bi2Se3 is an important compound for thermoelectric applications, and Co is frequently used as a diffusion barrier. This study investigated the interfacial reactions between electroplated Co and Bi2Se3 at 300℃, 400℃, and 500℃. The Co-Bi-Se isothermal sections at these temperatures were also investigated. The isothermal sections at 300℃ and 400℃ contain the phases (Co), Liquid(Bi), Liquid(Se), Co9Se8, CoSe2, β-Co1-xSe, (Bi2)m(Bi2Se3)n, and Bi2Se3, all of which exhibit extremely low ternary solubilities. At 500℃, the Co9Se8 phase is no longer present. In the Co/Bi2Se3 couple reacted at 300℃, two reaction phases, β-Co1-xSe and (Bi2)m(Bi2Se3)n, are formed. Similar results are found in the Co/Bi2Se3 couple reacted at 400℃. The diffusion path is Co/β-Co1-xSe/(Bi2)m(Bi2Se3)n/Bi2Se3. As the temperature increases to 500℃, the formation of the Liquid(Bi) phase adjacent to the β-Co1-xSe phase was observed. |