Abstract
The ternary chalcopyrite CuGaTe2 has emerged as a promising p-type thermoelectric material with its advantages of low cost,good stability,and non-toxic elements.However,its thermoelectric performance is limited by the intrinsic low electrical conductivity and high lattice thermal conductivity.In this work,A deficiency of Cu in Cu1-xGaTe2 semiconductors can be used to optimize the electrical properties by im-proving the carrier concentration and to reduce thermal conductivity through multi-scale phonon scat-tering,which is predicted and guided by the First-principles density functional theory calculations.The carrier concentration is increased to 1020,which compensates for the low electrical performance caused by the intrinsic low nH of CuGaTe2.The average power factor of Cu0.96GaTe2 reaches 106.3％higher than that of the original CuGaTe2.In addition,the lattice thermal conductivity of the defective samples is greatly reduced at high temperatures,which is mainly due to the reduction of sound speed and phonon scattering.All the above factors contribute to the highest dimensionless figure of merit(ZT)value of 1.23 at 823 K in Cu0.96GaTe2,which is 114％higher than the pristine CuGaTe2,and the average ZT is 171.4％higher.
基金项目
国家自然科学基金(51871240)
research computing facilities were supported by the National Supercomputing Center in Shenzhen(Shenzhen Cloud Computing Cent()
NETL
NSTL
维普
万方数据