Enhancement in Power Factor of Al-Doped Cu2Se Thermoelectric Compound Prepared by Combustion Synthesis via Spark Plasma Sintering Technique

Abstract

An attempt was made to dope the aluminium in the copper site of the Cu₂Se compound via combustion synthesis during spark plasma sintering. A series of Cu_2−xAl_xSe (x = 0, 0.01, 0.02, 0.03) materials were prepared by combustion synthesis during spark plasma sintering and short annealing. The X-Ray diffraction reports reveal that the prepared materials like Cu₂Se consist of α—Cu₂Se phase, Cu_1.99Al_0.01Se, Cu_1.98Al_0.02Se consist of a mixture of α—Cu₂Se and β—Cu₂Se phases, and Cu_1.97Al_0.03Se consist of β—Cu₂Se phase. The doping of aluminium enhances the electrical conductivity and power factor value. Furthermore, Al-doping causes the Al–Cu secondary phase formation and aluminium cluster, which also significantly affect the electrical properties of the compounds. The sample Cu_1.98Al_0.02Se exhibits a power factor of 13.73 at 700 °C, which is 23.5% higher than the pure Cu₂Se sample prepared.

Graphical Abstract