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.