中国物理B ›› 2018, Vol. 27 ›› Issue (4): 47211-047211.doi: 10.1088/1674-1056/27/4/047211

所属专题： SPECIAL TOPIC — Recent advances in thermoelectric materials and devices

• TOPIC REVIEW—Thermal and thermoelectric properties of nano materials • 上一篇    下一篇

Enhanced thermoelectric properties of p-type polycrystalline SnSe by regulating the anisotropic crystal growth and Sn vacancy

Chengyan Liu(刘呈燕), Lei Miao(苗蕾), Xiaoyang Wang(王潇漾), Shaohai Wu(伍少海), Yanyan Zheng(郑岩岩), Ziyang Deng(邓梓阳), Yulian Chen(陈玉莲), Guiwen Wang(王桂文), Xiaoyuan Zhou(周小元)   

  1. 1. Guangxi Key Laboratory of Information Material, Guangxi Collaborative Innovation Center of Structure and Property for New Energy and Materials, School of Material Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China;
    2. College of Physics, Chongqing University, Chongqing 401331, China
  • 收稿日期:2018-03-01 修回日期:2018-03-19 出版日期:2018-04-05 发布日期:2018-04-05
  • 通讯作者: Lei Miao E-mail:miaolei@guet.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 51572049, 51562005, and 51772056), the Natural Science Foundation of Guangxi Zhuang Automomous Region, China (Grant Nos. 2015GXNSFFA139002 and 2016GXNSFBA380152), and the Open Fund of Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences (Grant No. CRYO201703).

Enhanced thermoelectric properties of p-type polycrystalline SnSe by regulating the anisotropic crystal growth and Sn vacancy

Chengyan Liu(刘呈燕)1, Lei Miao(苗蕾)1, Xiaoyang Wang(王潇漾)1, Shaohai Wu(伍少海)1, Yanyan Zheng(郑岩岩)1, Ziyang Deng(邓梓阳)1, Yulian Chen(陈玉莲)1, Guiwen Wang(王桂文)2, Xiaoyuan Zhou(周小元)2   

  1. 1. Guangxi Key Laboratory of Information Material, Guangxi Collaborative Innovation Center of Structure and Property for New Energy and Materials, School of Material Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China;
    2. College of Physics, Chongqing University, Chongqing 401331, China
  • Received:2018-03-01 Revised:2018-03-19 Online:2018-04-05 Published:2018-04-05
  • Contact: Lei Miao E-mail:miaolei@guet.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 51572049, 51562005, and 51772056), the Natural Science Foundation of Guangxi Zhuang Automomous Region, China (Grant Nos. 2015GXNSFFA139002 and 2016GXNSFBA380152), and the Open Fund of Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences (Grant No. CRYO201703).

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摘要： Thermoelectric selenides have attracted more and more attentions recently. Herein, p-type SnSe polycrystalline bulk materials with good thermoelectric properties are presented. By using the SnSe2 nanostructures synthesized via a wet-chemistry route as the precursor, polycrystalline SnSe bulk materials were successfully obtained by a combined heat-treating process under reducing atmosphere and following spark plasma sintering procedure. As a reference, the SnSe nanostructures synthesized via a wet-chemistry route were also fabricated into polycrystalline bulk materials through the same process. The thermoelectric properties of the SnSe polycrystalline transformed from SnSe2 nanostructures indicate that the increasing of heattreating temperature could effectively decrease the electrical resistivity, whereas the decrease in Seebeck coefficient is nearly invisible. As a result, the maximum power factor is enhanced from 5.06×10-4 W/m·K2 to 8.08×10-4 W/m·K2 at 612℃. On the other hand, the reference sample, which was obtained by using SnSe nanostructures as the precursor, displays very poor power factor of only 1.30×10-4 W/m·K2 at 537℃. The x-ray diffraction (XRD), scanning electron microscope (SEM), x-ray fluorescence (XRF), and Hall effect characterizations suggest that the anisotropic crystal growth and existing Sn vacancy might be responsible for the enhanced electrical transport in the polycrystalline SnSe prepared by using SnSe2 precursor. On the other hand, the impact of heat-treating temperature on thermal conductivity is not obvious. Owing to the boosting of power factor, a high zT value of 1.07 at 612℃ is achieved. This study provides a new method to synthesize polycrystalline SnSe and pave a way to improve the thermoelectric properties of polycrystalline bulk materials with similar layered structure.

关键词: thermoelectric properties, SnSe2 nanostructures, polycrystalline SnSe, anisotropic crystal growth

Abstract: Thermoelectric selenides have attracted more and more attentions recently. Herein, p-type SnSe polycrystalline bulk materials with good thermoelectric properties are presented. By using the SnSe2 nanostructures synthesized via a wet-chemistry route as the precursor, polycrystalline SnSe bulk materials were successfully obtained by a combined heat-treating process under reducing atmosphere and following spark plasma sintering procedure. As a reference, the SnSe nanostructures synthesized via a wet-chemistry route were also fabricated into polycrystalline bulk materials through the same process. The thermoelectric properties of the SnSe polycrystalline transformed from SnSe2 nanostructures indicate that the increasing of heattreating temperature could effectively decrease the electrical resistivity, whereas the decrease in Seebeck coefficient is nearly invisible. As a result, the maximum power factor is enhanced from 5.06×10-4 W/m·K2 to 8.08×10-4 W/m·K2 at 612℃. On the other hand, the reference sample, which was obtained by using SnSe nanostructures as the precursor, displays very poor power factor of only 1.30×10-4 W/m·K2 at 537℃. The x-ray diffraction (XRD), scanning electron microscope (SEM), x-ray fluorescence (XRF), and Hall effect characterizations suggest that the anisotropic crystal growth and existing Sn vacancy might be responsible for the enhanced electrical transport in the polycrystalline SnSe prepared by using SnSe2 precursor. On the other hand, the impact of heat-treating temperature on thermal conductivity is not obvious. Owing to the boosting of power factor, a high zT value of 1.07 at 612℃ is achieved. This study provides a new method to synthesize polycrystalline SnSe and pave a way to improve the thermoelectric properties of polycrystalline bulk materials with similar layered structure.

Key words: thermoelectric properties, SnSe2 nanostructures, polycrystalline SnSe, anisotropic crystal growth

中图分类号:  (Thermoelectric and thermomagnetic effects)

  • 72.20.Pa
72.15.Jf (Thermoelectric and thermomagnetic effects) 72.80.Jc (Other crystalline inorganic semiconductors) 81.07.-b (Nanoscale materials and structures: fabrication and characterization)