摘要
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.
基金
supported by National Natural Science Foundation of China(No.52061034 and 51971052)
Natural Science Foundation of Inner Mongolia(No.2021LHBS05001)
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).
