Synthesis of chalcogenide compounds for energy harvesting applications

Abstract

The effect of ZnTe incorporation on PbTe to increase thermoelectric performance by valence band convergence was examined. Also structural and spectroscopic characterizations were noted from the theoretical calculations, and thermoelectric transport properties of Pb0.985Na0.015Te-x% ZnTe (x = 0, 1, 2, 4). The fact that solid solubility limit of ZnTe in PbTe is less than 1 mol% is studied. A tendency of Hall coefficients with ZnTe contents implies that valence band is a little converged. Therefore, there was no significant enhancement in the Seebeck coefficient. But, the lattice thermal conductivity was reduced from introduction of ZnTe in p-type Pb0.985Na0.015Te. In conclusion, the spark plasma sintered Pb0.985Na0.015Te-2% ZnTe reaches the best ZT of 1.73 at 700K, which arises from a relatively high power factor of ~27.0 μW cm-1 K-2 and a low lattice thermal conductivity of ~0.69 W m-1 K-1 at ~700 K.