高压烧结对n型PbTe基材料热电性能的影响

 采用高压烧结技术制备了按偏离化学计量比配制的PbTe基热电材料（Pb_0.55Te_0.45），重点研究了烧结压力对材料热电性能的影响。研究结果表明：高压烧结过程能有效降低材料中的晶格缺陷，从而显著改变样品中的载流子浓度及其迁移率。与未经烧结的常压熔融样品相比，高压烧结样品的Seebeck系数得到大幅提高，电导率略有降低，室温热导率降低了50%，所以高压烧结样品的品质因子得到较大提高。当烧结压力为2 GPa时，所得样品在700 K时其品质因子达到0.59，相比未经烧结的常压熔融样品提高了150%。

Effect of High Pressure Sintering on the Thermoelectric Properties of n-Type PbTe

The n-type nonstoichiometric PbTe(Pb0.55Te0.45) materials were prepared by the high pressure sintering process.The emphasis of the present study is on the influence of the pressure on the thermoelectric properties of the material.The experimental results show that the lattice defects are removed by high pressure sintering process,and it effectively adjusts the carrier concentration and its transport properties.Compared with the melting ingots,the Seebeck coefficient of the high pressure sintering sample obtains enhancement largely,the electric conductivity slightly reduces,simultaneously the thermal conductivity is low,and therefore the figure of merit(Tα2σ/κ) of the high pressure sintering sample is greatly enhanced.Therefore,the maximum the figure of merit of the sample prepared by 2 GPa reaches 0.59 at 700 K,which is about 150% improvement in comparison with the melting ingot.