Turning waste heat into electricity using thermoelectric materials supports the crucial goals of the sustainable development. Two ternary chalcogenide compounds, the AgSbTe2 and AgSbSe2, are viewed as prospective candidates for mid-temperature waste heat recovery (600-800 K). Alloying between the cubic AgSbTe2 and AgSbSe2 yields to the very high zT peak value of 1.4 in Ag25Sb25Se10Te40 and Ag25Sb25Se5Te45 at 680 K, which are nearly 40% and 250% higher than those of undoped AgSbTe2 (zT ∼ 1) and AgSbSe2 (zT ∼ 0.4). The relations between the phase stability, the carrier concentration and the electronic/thermal transport property are understood by conducting comprehensive study along the pseudo-binary AgSbSe2-AgSbTe2 system with varying values of x and y in Ag50-xSbxSe50-yTey (25 ≤ x ≤ 30, y ≤ 50).
- Phase diagrams