摘要
Sulfide nanocrystals and their composites have shown great potential in the thermoelectric(TE)field due to their extremely low thermal conductivity.Recently a solid and hollow metastable Au2S nanocrystalline has been successfully synthesized.Herein,we study the TE properties of this bulk Au2S by first-principles calculations and semiclassical Boltzmann transport theory,which provides the basis for its further experimental studies.Our results indicate that the highly twofold degeneracy of the bands appears at theΓpoint in the Brillouin zone,resulting in a high Seebeck coefficient.Besides,Au2S exhibits an ultra-low lattice thermal conductivity(~0.88 W·m^-1·K^-1 at 700 K).At 700 K,the thermoelectric figure of merit of the optimal p-type doping is close to 1.76,which is higher than 0.8 of ZrSb at 700 K and 1.4 of PtTe at 750 K.Our work clearly demonstrates the advantages of Au2S as a TE material and would greatly inspire further experimental studies and verifications.
作者
Y Y Wu
X L Zhu
H Y Yang
Z G Wang
Y H Li
B T Wang
伍义远;朱雪良;杨恒玉;王志光;李玉红;王保田(School of Nuclear Science and Technology,Lanzhou University,Lanzhou 730000,China;Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China;Spallation Neutron Source Science Center,Dongguan 523808,China;School of Materials Science and Engineering,Hunan University of Science and Technology,Xiangtan 411201,China;Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,China;Collaborative Innovation Center of Extreme Optics,Shanxi University,Taiyuan 030006,China)
基金
the National Natural Science Foundation of China(Grant Nos.11504312,11775102,and 11805088)
the National Basic Research Program of China(Grant No.2015CB921103)
China Postdoctoral Science Foundation(Grant No.2018M641477)
Guangdong Provincial Department of Science and Technology,China(Grant No.2018A0303100013)
the Fundamental Research Funds for the Central Universities,China(Lanzhou University,Grant No.lzujbky-2018-19).
