Thermoelectric Properties of Cu2Se Compound Fabricated at Low-Temperature Combustion Synthesis as a New Approach with Alternative Techniques

• Published in: Journal of electronic materials Vol. 52; no. 3; pp. 2168 - 2176
• Main Authors: Thangavel, N., Kumaran, S.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.03.2023; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Combustion synthesis; Copper selenides; Densification; Electronics and Microelectronics; Homogeneity; Instrumentation; Intermetallic compounds; Ion migration; Low temperature; Materials Science; Mechanical alloying; Optical and Electronic Materials; Original Research Article; Plasma sintering; Selenium; Sintering (powder metallurgy); Solid State Physics; Spark plasma sintering; Specific gravity; Thermoelectricity; thermoelectric; phase transition; spark plasma sintering; Combustion reaction
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-022-10196-7

This article report the combustion synthesis of a Cu 2 Se thermoelectric intermetallic compound via spark plasma sintering (SPS). The elemental copper and selenium powder mixture makes a combustion reaction at ~ 130°C during spark plasma-assisted heating. The applied load and combustion reaction together facilitate the densification of the reacted compound to a relative density of 88%. The x-ray diffractometer (XRD) data of the as-sintered bulk reacted compound confirms the formation of α -Cu 2 Se and β -Cu 2 Se compounds. On further short annealing at 350°C for 10 min, the β -Cu 2 Se transforms to α -Cu 2 Se and a complete monoclinic α -Cu 2 Se phase is obtained in the compound. The highest figure-of-merit (ZT) value of 0.61 at 650 K was achieved. This low-temperature sintering approach helps to overcome the issue of copper ion migration during SPS, and hence the chemical homogeneity is ascertained throughout the compound. The thermoelectric properties were compared with the Cu 2 Se material synthesized from other routes and found a superior ZT value than material prepared from solvothermal synthesis, mechanical alloying and hydrothermal-hot press techniques. Graphical Abstract