气候变化领域集成服务门户(CCPortal): Enhancing thermoelectric performance in hierarchically structured BiCuSeO by increasing bond covalency and weakening carrier-phonon coupling

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DOI	10.1039/c7ee00464h
	Enhancing thermoelectric performance in hierarchically structured BiCuSeO by increasing bond covalency and weakening carrier-phonon coupling
	Ren G.-K.; Wang S.-Y.; Zhu Y.-C.; Ventura K.J.; Tan X.; Xu W.; Lin Y.-H.; Yang J.; Nan C.-W.
发表日期	2017
ISSN	17545692
起始页码	1590
结束页码	1599
卷号	10 期号:7
英文摘要	BiCuSeO oxyselenides are promising thermoelectric materials at intermediate temperatures, primarily due to their ultralow lattice thermal conductivity (κL) and high Seebeck coefficient. The intrinsically low carrier mobility in these materials, normally below ∼20 cm2 V-1 s-1 at 300 K, however, largely limits further improvements of their thermoelectric properties. In this study, by introducing less electronegative Te into the conductive Cu-Se layers, we demonstrate that the enhanced chemical bond covalency results in smaller effective mass and thus improved carrier mobility, through the weakening of carrier-phonon coupling. The improved carrier mobility by Te-doping largely retains the electrical conductivity values and thus high power factors even with decreased carrier concentrations. Meanwhile, the hierarchical structural features including dual point defects, nanoinclusions, grain boundaries, etc., originating from the nonequilibrium self-propagating high-temperature synthesis (SHS) processes, further reduce κL close to the amorphous limit. Ultimately, a maximum ZT value of ∼1.2 at 873 K is achieved in Bi0.96Pb0.04CuSe0.95Te0.05O, ∼35% improvement as compared with that of Te-free Bi0.96Pb0.04CuSeO and ∼2.4 times higher than that of the pristine sample. Furthermore, our study elucidates that weakening of carrier-phonon coupling through regulating chemical bonding within the conductive functionalities can be an effective avenue for further improving the thermoelectric performance of BiCuSeO. © The Royal Society of Chemistry 2017.
英文关键词	Carrier mobility; Chemical bonds; Grain boundaries; Phonons; Point defects; Thermal conductivity; Thermoelectric equipment; Carrier-phonon coupling; Electrical conductivity; Intermediate temperatures; Lattice thermal conductivity; Self-propagating high-temperature synthesis process; Thermo-Electric materials; Thermoelectric performance; Thermoelectric properties; Thermoelectricity; chemical bonding; chemical compound; electrical conductivity; hierarchical system; high temperature; mobility; performance assessment; thermal conductivity; thermal power
语种	英语
来源期刊	Energy & Environmental Science
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/190457
作者单位	State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China; Materials Science and Engineering Department, University of Washington, Seattle, WA 98195, United States; Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China; Department of Chemical and Biomolecular Engineering, University of Florida, Gainesville, FL 32610, United States
推荐引用方式 GB/T 7714	Ren G.-K.,Wang S.-Y.,Zhu Y.-C.,et al. Enhancing thermoelectric performance in hierarchically structured BiCuSeO by increasing bond covalency and weakening carrier-phonon coupling[J],2017,10(7).
APA	Ren G.-K..,Wang S.-Y..,Zhu Y.-C..,Ventura K.J..,Tan X..,...&Nan C.-W..(2017).Enhancing thermoelectric performance in hierarchically structured BiCuSeO by increasing bond covalency and weakening carrier-phonon coupling.Energy & Environmental Science,10(7).
MLA	Ren G.-K.,et al."Enhancing thermoelectric performance in hierarchically structured BiCuSeO by increasing bond covalency and weakening carrier-phonon coupling".Energy & Environmental Science 10.7(2017).