Efficient interlayer charge release for high-performance layered thermoelectrics

作     者：Hao Zhu Zhou Li Chenxi Zhao Xingxing Li Jinlong Yang Chong Xiao Yi Xie Hao Zhu;Zhou Li;Chenxi Zhao;Xingxing Li;Jinlong Yang;Chong Xiao;Yi Xie

作者机构：Hefei National Laboratory for Physical Sciences at the MicroscaleUniversity of Science and Technology of China Institute of EnergyHefei Comprehensive National Science Center Department of Chemical PhysicsHefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information & Quantum PhysicsUniversity of Science and Technology of China 

出 版 物：《National Science Review》 (国家科学评论(英文版))

年 卷 期：2021年第8卷第2期

页      面：115-122页

核心收录：

学科分类：07[理学] 070205[理学-凝聚态物理] 0702[理学-物理学] 

基　　金：supported by the National Key R&D Program of China (2018YFB0703602 and 2017YFA0303500) the National Natural Science Foundation of China (21622107, U1832142and 21805269) the Key Research Program of Frontier Sciences(QYZDY-SSW-SLH011) the Youth Innovation Promotion Association CAS (2016392) the China Postdoctoral Science Foundation (2017M620261) the National Postdoctoral Program for Innovative Talents (BX201700217) the Anhui Provincial Natural Science Foundation (1808085QA08) the Fundamental Research Funds for the Central Universities(WK2340000094 and WK2060190090) 

主　　题：layered superlattice material interlayer charge release carrier concentration thermoelectric performance 

摘      要：Many layered superlattice materials intrinsically possess large Seebeck coefficient and low lattice thermal conductivity, but poor electrical conductivity because of the interlayer transport barrier for charges, which has become a stumbling block for achieving high thermoelectric performance. Herein, taking Bi Cu Se O superlattice as an example, it is demonstrated that efficient interlayer charge release can increase carrier concentration, thereby activating multiple Fermi pockets through Bi/Cu dual vacancies and Pb *** results reveal that the extrinsic charges, which are introduced by Pb and initially trapped in the charge-reservoir [BiO]sublayers, are effectively released into [CuSe]sublayers via the channels bridged by Bi/Cu dual vacancies. This efficient interlayer charge release endows dual-vacancy-and Pb-codoped Bi Cu Se O with increased carrier concentration and electrical conductivity. Moreover, with increasing carrier concentration, the Fermi level is pushed down, activating multiple converged valence bands, which helps to maintain a relatively high Seebeck coefficient and yield an enhanced power factor. As a result, a high ZT value of 1.4 is achieved at 823 K in codoped BiPbCuSeO, which is superior to that of pristine Bi Cu Se O and solely doped samples. The present findings provide prospective insights into the exploration of high-performance thermoelectric materials and the underlying transport physics.