Antimony-based Zintl compounds AM2Sb2(A=Ca,Sr,Ba,Yb,Eu;M=Mg,Zn,Cd,Mn),which enable a broad range of manipulation on electrical and thermal transport properties,are considered as an important class of thermoelectric ma...Antimony-based Zintl compounds AM2Sb2(A=Ca,Sr,Ba,Yb,Eu;M=Mg,Zn,Cd,Mn),which enable a broad range of manipulation on electrical and thermal transport properties,are considered as an important class of thermoelectric materials.Phonon and carrier transport engineering were realized in YbMg2Sb2 via equivalent and aliovalent substitution of Zn and Ag,respectively.The roomtemperature thermal conductivity reduces from 1.96 to 1.15 W m^-1 K^-1 for YbMg2-xZnxSb2 due to the mass and strain fluctuation through the formation of the absolute solid solution of YbMg2Sb2-YbZn2Sb2.Furthermore,the carrier concentration has been further optimized by Ag doping(from 0.42×10^19 to 7.72×10^19 cm^-3 at room temperature),and thus the electrical conductivity and the power factor are enhanced effectively.The integrated aspects make the dimensionless figure of merit(zT)reach 0.48 at 703 K,which is 60%higher than the pristine YbMgZnSb2 sample.展开更多
基金supported by the National Key Research and Development Program of China (2018YFA0702100)the National Natural Science Foundation of China (21771123)+2 种基金the Programme of Introducing Talents of Discipline to Universities (D16002)the Science and Technology Commission of Shanghai Municipality (15DZ2260300)Key Laboratory of Optoelectronic Materials Chemistry and Physics, Chinese Academy of Sciences (2008DP173016)
文摘Antimony-based Zintl compounds AM2Sb2(A=Ca,Sr,Ba,Yb,Eu;M=Mg,Zn,Cd,Mn),which enable a broad range of manipulation on electrical and thermal transport properties,are considered as an important class of thermoelectric materials.Phonon and carrier transport engineering were realized in YbMg2Sb2 via equivalent and aliovalent substitution of Zn and Ag,respectively.The roomtemperature thermal conductivity reduces from 1.96 to 1.15 W m^-1 K^-1 for YbMg2-xZnxSb2 due to the mass and strain fluctuation through the formation of the absolute solid solution of YbMg2Sb2-YbZn2Sb2.Furthermore,the carrier concentration has been further optimized by Ag doping(from 0.42×10^19 to 7.72×10^19 cm^-3 at room temperature),and thus the electrical conductivity and the power factor are enhanced effectively.The integrated aspects make the dimensionless figure of merit(zT)reach 0.48 at 703 K,which is 60%higher than the pristine YbMgZnSb2 sample.
