Thermoelectric properties of (HgTe)_(0.55)(PbTe)_(0.45) eutectic composite with In doping

摘要

This paper reports the microstructures and thermoelectric properties of In-doped (HgTe)(0)(.5)(5)(PbTe)(0.45) composites. X-ray diffraction and optical microscopy confirmed that all composites consisted of the HgTe and PbTe phases and formed a dendritic structure. Transmission electron microscopy revealed that In mostly displaced Hg in the HgTe. For x = 0.01 and 0.03, the electrical resistivity of (Hg1-xInxTe)(0)(.5)(5)(PbTe)(0.45) composites decreased significantly, while the sample with x = 0.05 showed increased value, compared with the parent composite. The measured Seebeck coefficient demonstrated that electrons dominated the thermoelectric transport in these composites. A considerable reduction in thermal conductivity was found after In doping, while heat conduction was dominated by lattice contribution in all composites. The maximum figure of merit and power factor values of 0.25 and 20 mu W/cmK(2), respectively, were obtained at 300 K for the x = 0.01 composite, which were almost an order of magnitude higher than those of the parent composite.