Bismuth sulfide(Bi_(2)S_(3))with an earth-abundant elemental composition has attracted wide attention as a promising n-type thermoelectric material in recent years.However,the thermoelectric performance of Bi_(2)S_(3)...Bismuth sulfide(Bi_(2)S_(3))with an earth-abundant elemental composition has attracted wide attention as a promising n-type thermoelectric material in recent years.However,the thermoelectric performance of Bi_(2)S_(3) is limited by its low electrical conductivity.It is therefore vital to choose an effective dopant for enhancing the electrical transport properties of Bi_(2)S_(3).In this work,by using the solid-state reaction and the spark plasma sintering technique,Bi_(2)S_(3) bulk materials doped with x mol%LaCl_(3)(x=0,1.0,2.0,3.0)were successfully fabricated.The conductivity of Bi_(2)S_(3) samples doped with 2 mol%LaCl_(3)(about 153 S cm^(-1))was one order of magnitude higher than that of the pristine Bi_(2)S_(3) sample,resulting in a high power factor of 483μW m-1 K-2 at 625 K.The lattice thermal conductivity of the doped samples decreased due to more grain boundaries,point defects and nano-precipitates.Consequently,a peak thermoelectric figure-of-merit(ZT)of 0.50 at 625 K was obtained for the Bi_(2)S_(3) sample with 2 mol%LaCl_(3) doping,which was over four times higher compared to that of pristine Bi_(2)S_(3)(about 0.11 at 625 K).The results suggest that the dopant LaCl_(3) is effective for modifying carrier concentration and reducing lattice thermal conductivity.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.11764025 and 51702150)supported by the Science,Technology,and Innovation Commission of Shenzhen Municipality(Grant No.KQCX2015033110182370 and JCYJ20150831142508365).
文摘Bismuth sulfide(Bi_(2)S_(3))with an earth-abundant elemental composition has attracted wide attention as a promising n-type thermoelectric material in recent years.However,the thermoelectric performance of Bi_(2)S_(3) is limited by its low electrical conductivity.It is therefore vital to choose an effective dopant for enhancing the electrical transport properties of Bi_(2)S_(3).In this work,by using the solid-state reaction and the spark plasma sintering technique,Bi_(2)S_(3) bulk materials doped with x mol%LaCl_(3)(x=0,1.0,2.0,3.0)were successfully fabricated.The conductivity of Bi_(2)S_(3) samples doped with 2 mol%LaCl_(3)(about 153 S cm^(-1))was one order of magnitude higher than that of the pristine Bi_(2)S_(3) sample,resulting in a high power factor of 483μW m-1 K-2 at 625 K.The lattice thermal conductivity of the doped samples decreased due to more grain boundaries,point defects and nano-precipitates.Consequently,a peak thermoelectric figure-of-merit(ZT)of 0.50 at 625 K was obtained for the Bi_(2)S_(3) sample with 2 mol%LaCl_(3) doping,which was over four times higher compared to that of pristine Bi_(2)S_(3)(about 0.11 at 625 K).The results suggest that the dopant LaCl_(3) is effective for modifying carrier concentration and reducing lattice thermal conductivity.
