Effects of Pb Doping on the Electrical Transport Performance of Cu 1.98 Se

Cu2−δSe is an eco-friendly thermoelectric candidate owing to Cu ions migration in its high-temperature beta phase, and meanwhile the liquid-like Cu ions deteriorate the stability and reliability of materials. Here, Pb2+ ion was introduced into the Cu1.98Se lattice to improve the thermoelectric properties and the stability. The Pb-doped Cu1.98−xPbxSe (x = 0–0.035) compounds prepared by a facile solvothermal synthesis and microwave sintering. The obtained results reveal that the power factor of the doped samples greatly improved up to 1454 μW m−1 K−2 at 800 K, which was about 22.5% higher than that of undoped Cu1.98Se. In addition, after 3 cycles of testing, the power factor of Cu1.98Se decreased by 57% at 800 K, and that of Cu1.965Pb0.015Se decreased by less than 30%.