Cu_(2)Te-based materials are a type of superionic conductor belonging to the class of phonon-liquid elec-tron-crystal materials and have achieved high ZT values by doping and nanostructuring.However,it is easy to form...Cu_(2)Te-based materials are a type of superionic conductor belonging to the class of phonon-liquid elec-tron-crystal materials and have achieved high ZT values by doping and nanostructuring.However,it is easy to form copper vacancies in Cu_(2)Te which leads to an excessive carrier concentration and then results in a low Seebeck coefficient.Hence,controlling copper ion migration and optimizing carrier concen-tration is essential to improve the thermoelectric performance of Cu_(2)Te.This paper reports high-performance Cu_(2)TeeAg_(2)Te composite with high application value in the low-middle temperature re-gion,which is achieved by fine tuning the carrier concentration using Fe addition and non-stoichiometric Te,as well as controlling the thermal conductivity of composite.A high ZT of~1.2 is obtained in AgCu_(0.97)Fe_(0.03)Te_(0.96)at a low temperature of 573 K.Meanwhile,the phase transition mechanism of Cu_(2)TeeAg_(2)Te and its effect on the thermoelectric transport performance are revealed that go beyond nanostructuring and single-doping,which provides a strong theoretical basis for research and perfor-mance improvement of thermoelectric materials in this system.展开更多
基金supported by National Natural Science Foundation of China(No.52061034 and 51971052)Natural Science Foundation of Inner Mongolia(No.2021LHBS05001)+2 种基金Research Program of science and technology in Universities of Inner Mongolia Autonomous Region(No.NJZY21325)Youth Science and Technology Talents Support Project of Inner Mongolia Autonomous Region(No.NJYT23002)the Liaoning Revitalization Talents Program(No.XLYC2007183).
文摘Cu_(2)Te-based materials are a type of superionic conductor belonging to the class of phonon-liquid elec-tron-crystal materials and have achieved high ZT values by doping and nanostructuring.However,it is easy to form copper vacancies in Cu_(2)Te which leads to an excessive carrier concentration and then results in a low Seebeck coefficient.Hence,controlling copper ion migration and optimizing carrier concen-tration is essential to improve the thermoelectric performance of Cu_(2)Te.This paper reports high-performance Cu_(2)TeeAg_(2)Te composite with high application value in the low-middle temperature re-gion,which is achieved by fine tuning the carrier concentration using Fe addition and non-stoichiometric Te,as well as controlling the thermal conductivity of composite.A high ZT of~1.2 is obtained in AgCu_(0.97)Fe_(0.03)Te_(0.96)at a low temperature of 573 K.Meanwhile,the phase transition mechanism of Cu_(2)TeeAg_(2)Te and its effect on the thermoelectric transport performance are revealed that go beyond nanostructuring and single-doping,which provides a strong theoretical basis for research and perfor-mance improvement of thermoelectric materials in this system.
