Baoguo Ren

Preparation and Thermoelectric Properties of N-type PbTe Doped with In and PbI2

Lead telluride is traditional thermoelectric material at middle temperature and widely applied for electricity generation. They have been attracting many scientists to research on. The paper reports an N-type PbTe materials with high thermoelectric performances based on the traditional halogen-doping mechanism with additional indium. The PbTe based materials doped indium and PbI2 are prepared by powder metallurgy technology. We use an intermediate frequency induced furnace for primary alloy preparation. The alloy shows very homogeneous with the desired composition. Then, the comminuted powder particles are hot pressed under certain temperature, pressure and so on. The prepared samples have been examined by FETEM and their thermoelectric properties have been measured. The results indicate that doping with the appropriate PbI2 and indium leads to remarkable improvement of the thermoelectric properties, and we gained high figure of merit over a wide temperature range

New Integration Technology for PbTe Element

The paper reports a new technology for integration of PbTe elements. In traditional procedure, the first step is to prepare PbTe materials, then to bond them together with electrodes. We press the PbTe powder together with the powder of electrode and buffer materials by powder metallurgy after PbTe alloy was prepared, and obtain the elements directly. The paper described the technical process in detail. The authors prepared some samples of N-type PbTe elements using the technology. The electrode, buffer, PbTe material and their interfaces of the prepared samples are characterized by SEM and ED. The contact resistances have been measured and compared with the sample prepared by traditional technology. The results indicate that the proposed technology is easy, economic and feasible. It may simplify preparation process of PbTe elements, reduce the times PbTe materials suffered at high temperature and decrease the contact resistance

Test Method for Heat to Electricity Conversion Efficiency of Thermoelectric Unicouple

The heat to electricity conversion efficiency is the basic parameter of thermoelectric element, thermoelectric unicouple and thermoelectric devices. The authors present a new test method for heat to electricity conversion efficiency of thermoelectric unicouple. The input heat of thermoelectric unicouple has been divided into two parts including the output electric power and output heat out of the unicouple cold side. The later has been determined by a thermoelectric heat meter. The thermoelectric heat meter has a high sensitivity, so that high test accuracy could be gained on the determination of heat out of the unicouple cold side. The paper presents test results for heat to electricity conversion efficiency of some thermoelectric unicouple, and discusses about the factors which affect the test results, especially about the calibration of the heat meter

The performance and analysis of N-type PbTe prepared by super high pressing

The authors prepared N-type PbTe samples by super high pressing. The performance of the samples has been reported and discussed in the paper. The authors measured the density and bending strength of the samples prepared with different super high pressing technological parameters in order to judge their mechanical properties, made SEM analysis in order to observe their microscopic structure, tested electrical conductivity, Seebeck coefficient and calculated the power factor in order to estimate their thermoelectric performance. Comparing data of samples prepared by super high pressing with those of samples prepared by cold press, it is evident that the performances of the samples by super high pressing under suitable technological conditions are better than those of the samples by cold press.