Improvement in the Thermoelectric Performance of Manganese Telluride With the Addition of Cu₂Se

Manganese telluride (MnTe) has been proposed to be a favorable candidate for middle range temperature thermoelectric (TE) material; whereas, the low carrier concentration and higher thermal conductivity have restricted its applications. Herein, a crucial role of Cu-ion in synthesized MnTe with the addition of Cu₂Se through mechanical alloying and hot press sintering facilitate the improvement of carrier density and thus enhanced power factor of MnTe with the incorporation of 8 at.% Cu₂Se due to novel liquid-like behavior of Cu-ion in Cu₂Se at elevated temperatures. Moreover, the excessive hole density of Cu₂Se and the undissolved nano-scale Cu₂Se results in a remarkable scattering of phonons and thus suppressed lattice thermal conductivity at higher temperatures. With this approach, the overall thermoelectric performance of MnTe + x at.% Cu₂Se was investigated and we found enhancement in the thermoelectric performance with the inclusion of Cu₂Se with a maximum ZT of ∼0.72 in 8 at.% Cu₂Se added MnTe sample at 873 K.