Nanocomposites from Solution-Synthesized PbTe-BiSbTe Nanoheterostructure with Unity Figure of Merit at Low-Medium Temperatures (500-600 K).

A scalable, low-temperature solution process is used to synthesize precursor material for Pb-doped Bi0.7 Sb1.3 Te3 thermoelectric nanocomposites. The controllable Pb-doping leads to the increase in the optical bandgap, thus delaying the onset of bipolar conduction. Furthermore, the solution synthesis enables nanostructuring, which greatly reduces thermal conductivity. As a result, this material exhibits a zT = 1 over the 513-613 K range.