Thermoelectric Properties of p-type In-doped Pb1-xSnxTe

Lead tin telluride based alloys are p-type materials for thermoelectric applications in the 50-600degC temperatures range. Optimization of the thermoelectric properties for optimal performance at various temperature ranges can be achieved by varying the composition (x values) in Pb_1-xSn_xTe alloys. A different approach for controlling the carrier concentration can be obtained by indium doping of Pb_1-xSn_xTe alloys at a fixed composition. According to this second approach, a controlled energy gap and specific lattice thermal conductivity can be obtained. This communication focuses on the development of Pb_0.5Sn_0.5 Te alloys doped to different levels of indium concentration. The preparation techniques included preparation of master alloys with the desired composition, comminuting to appropriate powder particle size, cold compaction, sintering and annealing. The prepared samples were examined by SEM, EDS, XRD and the transport properties were determined. Maximal power factor values in the range of 11-12 muW/cmK² were obtained at temperatures of 150, 250 and 380degC for indium doping of 0.5, 0.1 and 0.03at%In. respectively