The quaternary diamond-like compounds,A_(2)Cu_(3)In_(3)Te_(8)(A=Cd,Zn,Mn,Mg),are a new class of thermoelectric materials recently proposed by complex structure design.Among them,the Zn_(2)Cu_(3)In_(3)Te_(8) compound p...The quaternary diamond-like compounds,A_(2)Cu_(3)In_(3)Te_(8)(A=Cd,Zn,Mn,Mg),are a new class of thermoelectric materials recently proposed by complex structure design.Among them,the Zn_(2)Cu_(3)In_(3)Te_(8) compound possesses reasonable electrical transport properties but relatively high lattice thermal conductivity.Herein,the effects of Ag substitution on the phase stability and thermoelectric properties of Zn_(2)Cu_(3)In_(3)Te_(8) compound are reported.It is revealed that only the In sites show an appreciable tolerance for Ag doping.Ag substitution at the In sites introduces extra holes and thus results in improved electrical transport properties.Furthermore,the introducing of Ag lowers the sound velocities and enhances the phonon scattering of the Zn_(2)Cu_(3)In_(3)Te_(8) compound,which leads to a substantially reduction in lattice thermal conductivity.Finally,in virtue of the optimization in both electrical and thermal transport properties,the maximal zT value of Zn_(2)Cu_(3)In_(2.8)Ag_(0.2)Te_(8) sample reaches 0.62 at 823 K,which is 43%higher than the pristine sample.展开更多
基金This work was supported by the National Key Research and Development Program of China(grant nos.2018YFB0703600 and 2018YFA0702100)the National Natural Science Foundation of China(grant nos.51472241,51772186,51632005,and 51371194)the Science and Technology Commission of Shanghai Municipality(grant no.16DZ2260601).
文摘The quaternary diamond-like compounds,A_(2)Cu_(3)In_(3)Te_(8)(A=Cd,Zn,Mn,Mg),are a new class of thermoelectric materials recently proposed by complex structure design.Among them,the Zn_(2)Cu_(3)In_(3)Te_(8) compound possesses reasonable electrical transport properties but relatively high lattice thermal conductivity.Herein,the effects of Ag substitution on the phase stability and thermoelectric properties of Zn_(2)Cu_(3)In_(3)Te_(8) compound are reported.It is revealed that only the In sites show an appreciable tolerance for Ag doping.Ag substitution at the In sites introduces extra holes and thus results in improved electrical transport properties.Furthermore,the introducing of Ag lowers the sound velocities and enhances the phonon scattering of the Zn_(2)Cu_(3)In_(3)Te_(8) compound,which leads to a substantially reduction in lattice thermal conductivity.Finally,in virtue of the optimization in both electrical and thermal transport properties,the maximal zT value of Zn_(2)Cu_(3)In_(2.8)Ag_(0.2)Te_(8) sample reaches 0.62 at 823 K,which is 43%higher than the pristine sample.
