Enhancing thermoelectric performance of CuSe by doping Te.

Owing to the excellent electrical properties and inherently complex crystal structure, CuSe has been considered as a promising thermoelectric (TE) material. Herein, a series of CuSeTe (x = 0, 0.02, 0.04, 0.06, and 0.08) bulk samples are prepared by combining mechanical alloying (MA) and spark plasma sintering (SPS) to investigate the effect of Te content (x) on the phase structure, microstructure and TE properties of stoichiometric CuSe. It is found that a maximum TE figure of merit (ZT) value of 1.25 could be achieved for CuSeTe sample at 773 K, which essentially stemmed from the elevated power factor (PF) and reduced thermal conductivity (κ). The results obtained in our study indicate that the introduction of Te into stoichiometric CuSe is an effective and convenient strategy to improve ZT by enhancing PF and decreasing κ.