Introduction of porous structure:A feasible and promising method for improving thermoelectric performance of Bi2Te3 based bulks
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2018年第12期
论文作者：Jie Hu Xi’An Fan Chengpeng Jiang Bo Feng Qiusheng Xiang Guangqiang Li Zhu He Yawei Li
文章页码：2458 - 2463
摘 要：The porous p-type Bi0.4Sb1.6Te3 bulks containing irregularly and randomly oriented pores were obtained by artificially controlling the relative density of sintered samples during resistance pressing sintering process. It is demonstrated that the thermoelectric performances are significantly affected by the porous structure, especially for the electrical and thermal conductivity due to the enhanced carrier scattering and phonon scattering. The increasing porosity resulted in the obvious decrease in electrical and thermal conductivity, and little change in Seebeck coefficients. It is encouraging that the reduction of thermal conductivity can compensate for the deterioration of electrical performance, leading to the enhancement in thermoelectric figure of merit（ZT）. The maximum ZT value of 1.0 was obtained for the sample with a relative density of 90% at 333 K. Unfortunately, the increase in porosity also brought in obvious degradations in Vickers hardness from 51.71 to 27.74 HV. It is worth mentioning that although the Vickers hardness of the sample with a relative density of 90% decreased to 40.12 HV, it was still about twice as high as that of the zone melting sample（21.25 HV）. To summarize, introducing pores structure into bulks properly not only enhances the ZT value of Bi2Te3 based alloys, but also reduces the use of raw materials and saves production cost.
Jie Hu1,2，Xi’An Fan1,2，Chengpeng Jiang1,2，Bo Feng1,2，Qiusheng Xiang1,2，Guangqiang Li1，Zhu He1,2，Yawei Li1,2,3
1. The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology2. Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,Wuhan University of Science and Technology3. National-provincial Joint Engineering Research Center of High Temperature Materials and Lining Technology,Wuhan University of Science and Technology
摘 要：The porous p-type Bi0.4Sb1.6Te3 bulks containing irregularly and randomly oriented pores were obtained by artificially controlling the relative density of sintered samples during resistance pressing sintering process. It is demonstrated that the thermoelectric performances are significantly affected by the porous structure, especially for the electrical and thermal conductivity due to the enhanced carrier scattering and phonon scattering. The increasing porosity resulted in the obvious decrease in electrical and thermal conductivity, and little change in Seebeck coefficients. It is encouraging that the reduction of thermal conductivity can compensate for the deterioration of electrical performance, leading to the enhancement in thermoelectric figure of merit（ZT）. The maximum ZT value of 1.0 was obtained for the sample with a relative density of 90% at 333 K. Unfortunately, the increase in porosity also brought in obvious degradations in Vickers hardness from 51.71 to 27.74 HV. It is worth mentioning that although the Vickers hardness of the sample with a relative density of 90% decreased to 40.12 HV, it was still about twice as high as that of the zone melting sample（21.25 HV）. To summarize, introducing pores structure into bulks properly not only enhances the ZT value of Bi2Te3 based alloys, but also reduces the use of raw materials and saves production cost.
关键词：
