Enhancing Thermoelectric Properties of (Cu(2)Te)(1−x)-(BiCuTeO)(x) Composites by Optimizing Carrier Concentration

Because of the high carrier concentration, copper telluride (Cu(2)Te) has a relatively low Seebeck coefficient and high thermal conductivity, which are not good for its thermoelectric performance. To simultaneously optimize carrier concentration, lower thermal conductivity and improve the stability, BiCuTeO, an oxygen containing compound with lower carrier concentration, is in situ formed in Cu(2)Te by a method of combining self-propagating high-temperature synthesis (SHS) with spark plasma sintering (SPS). With the incorporation of BiCuTeO, the carrier concentration decreased from 8.1 × 10(20) to 3.8 × 10(20) cm(−3), bringing the increase of power factor from ~1.91 to ~2.97 μW cm(−1) K(−2) at normal temperature. At the same time, thermal conductivity reduced from 2.61 to 1.48 W m(−1) K(−1) at 623 K. Consequently, (Cu(2)Te)(0.95)-(BiCuTeO)(0.05) composite sample reached a relatively high ZT value of 0.13 at 723 K, which is 41% higher than that of Cu(2)Te.