Synergistically enhanced thermoelectric properties of Bi2S3 bulk materials via Cu interstitial doping and BiCl3 alloying

• 作者: Jun Guo Zi-Yuan Wang Yu-Ke Zhu Lin Chen Jing Feng Zhen-Hua Ge
• 来源期刊: 稀有金属（英文版）
• 年，卷（期）: 2022,（3）
• 所属期刊栏目: ORIGINAL ARTICLES
• 页码范围: 931-941
• 页数: 11页
• 语种: 英文

摘要

Bi2S3 is composed of inexpensive and environ-mental friendliness elements,which has received extensive interests and been investigated as a promising mid-tempera-ture thermoelectric material for years.Even pure Bi2S3 pos-sesses a high Seebeck coefficient and low thermal conductivity,its low electrical conductivity leads to a low figure of merit(ZT)value.In this work,Bi2S3 fabricated by solid-state melting combined with spark plasma sintering can significantly enhance the thermoelectric performance via introducing small amounts of Cu and BiCl3.Cu interstitial doping and Cl substitution on S site result in a large increase in electrical conductivity.Additionally,the enhanced phonon scattering is derived from the point defects caused by element doping,the grain boundaries,and the small amount of sec-ondary phase,which leads to the low thermal conductivity.Finally,a high ZT value of 0.7 is obtained at 773 K and reaches a large average ZT of 0.36 in the temperature range from room temperature(RT)to 773 K for the Cu-interstitial-dopedandBiCl3-alloyed(Cu0.01Bi2S3+0.175 mol％BiCl3)sample.Furthermore,the mechanical properties of the Cu0.01Bi2S3+0.175 mol％BiCl3 sample are lower than those of other Bi2S3 samples,which stem from the weak chemical bonding strength.