中国物理B ›› 2016, Vol. 25 ›› Issue (1): 17202-017202.doi: 10.1088/1674-1056/25/1/017202

• SPECIAL TOPIC—Soft matter and biological physics (Review) • 上一篇    下一篇

Unexpected low thermal conductivity and large power factor in Dirac semimetal Cd3As2

Cheng Zhang(张成), Tong Zhou(周通), Sihang Liang(梁斯航), Junzhi Cao(曹钧植),Xiang Yuan(袁翔), Yanwen Liu(刘彦闻), Yao Shen(沈瑶), Qisi Wang(王奇思),Jun Zhao(赵俊), Zhongqin Yang(杨中芹), Faxian Xiu(修发贤)   

  1. 1. State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
    2. Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, China;
    3. Key Laboratory for Computational Physical Sciences (MOE), Fudan University, Shanghai 200433, China
  • 收稿日期:2015-11-25 修回日期:2015-11-25 出版日期:2016-01-05 发布日期:2016-01-05
  • 通讯作者: Faxian Xiu E-mail:faxian@fudan.edu.cn

Unexpected low thermal conductivity and large power factor in Dirac semimetal Cd3As2

Cheng Zhang(张成)1,2, Tong Zhou(周通)1,2,3, Sihang Liang(梁斯航)1,2, Junzhi Cao(曹钧植)1,2,Xiang Yuan(袁翔)1,2, Yanwen Liu(刘彦闻)1,2, Yao Shen(沈瑶)1,2, Qisi Wang(王奇思)1,2,Jun Zhao(赵俊)1,2, Zhongqin Yang(杨中芹)1,2,3, Faxian Xiu(修发贤)1,2   

  1. 1. State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
    2. Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, China;
    3. Key Laboratory for Computational Physical Sciences (MOE), Fudan University, Shanghai 200433, China
  • Received:2015-11-25 Revised:2015-11-25 Online:2016-01-05 Published:2016-01-05
  • Contact: Faxian Xiu E-mail:faxian@fudan.edu.cn

摘要:

Thermoelectrics has long been considered as a promising way of power generation for the next decades. So far, extensive efforts have been devoted to the search of ideal thermoelectric materials, which require both high electrical conductivity and low thermal conductivity. Recently, the emerging Dirac semimetal Cd3As2, a three-dimensional analogue of graphene, has been reported to host ultra-high mobility and good electrical conductivity as metals. Here, we report the observation of unexpected low thermal conductivity in Cd3As2, one order of magnitude lower than the conventional metals or semimetals with a similar electrical conductivity, despite the semimetal band structure and high electron mobility. The power factor also reaches a large value of 1.58 mW·m-1·K-2 at room temperature and remains non-saturated up to 400 K. Corroborating with the first-principles calculations, we find that the thermoelectric performance can be well-modulated by the carrier concentration in a wide range. This work demonstrates the Dirac semimetal Cd3As2 as a potential candidate of thermoelectric materials.

关键词: Dirac semimetal, thermal conductivity, power factor, thermoelectric material

Abstract:

Thermoelectrics has long been considered as a promising way of power generation for the next decades. So far, extensive efforts have been devoted to the search of ideal thermoelectric materials, which require both high electrical conductivity and low thermal conductivity. Recently, the emerging Dirac semimetal Cd3As2, a three-dimensional analogue of graphene, has been reported to host ultra-high mobility and good electrical conductivity as metals. Here, we report the observation of unexpected low thermal conductivity in Cd3As2, one order of magnitude lower than the conventional metals or semimetals with a similar electrical conductivity, despite the semimetal band structure and high electron mobility. The power factor also reaches a large value of 1.58 mW·m-1·K-2 at room temperature and remains non-saturated up to 400 K. Corroborating with the first-principles calculations, we find that the thermoelectric performance can be well-modulated by the carrier concentration in a wide range. This work demonstrates the Dirac semimetal Cd3As2 as a potential candidate of thermoelectric materials.

Key words: Dirac semimetal, thermal conductivity, power factor, thermoelectric material

中图分类号:  (Thermoelectric and thermomagnetic effects)

  • 72.20.Pa
72.20.Jv (Charge carriers: generation, recombination, lifetime, and trapping) 72.15.-v (Electronic conduction in metals and alloys)