热压法制备P型Bi2Te3基温差电材料研究

以P型赝二元Bi2Te3-Sb2Te3体系温差电材料区熔晶棒为前驱体,采用真空热压烧结法制备材料样品。测试热压前后材料样品性能,测试结果表明:热压样品较区熔材料具有更高的致密度和机械强度,改善了Bi2Te3基温差电材料易沿解理面发生劈裂的现象;同时,热压工艺促使了材料内部晶体结构和载流子浓度的变化,引起材料电导率的降低和塞贝克系数的改变,导致材料热导率显著降低。综合考虑材料各项性能参数,热压材料的热电优值基本与区熔材料相当,但前者的力学强度明显优于后者,在实际使用中将占有明显的优势。

Preparation of P-type Bi2Te3 based thermoelectric material by hot pressing

In this article,with the p-type pseudo-binary thermoelectric material Bi2Te3-Sb2Te3as the precursor,the samples were prepared with vacuum hot pressing technology,and their properties were measured before and after the hot pressing.The results indicate that the hot pressing samples have higher density and mechanical strength,which improves the phenomenon of splitting along the cleavage plane.Meanwhile,the hot pressing method changes the crystal structure and carrier concentration in the materials,which lead to the decrease of electric conductivity and the change of Seebeck coefficient,and then results in the decrease of thermal conductivity.For comprehensive consideration,the thermoelectric figure of merit of the hot pressing material is basically equivalent to that of zone-melting samples,but the mechanical properties of the former are much better than the later,which will provide a great advantage in practical application.