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Influence of Compensating Defect Formation on the Doping Efficiency and Thermoelectric Properties of Cu_(2-y)Se_(1–x)Br_x

Day, Tristan W. and Weldert, Kai S. and Zeier, Wolfgang G. and Chen, Bor-Rong and Moffitt, Stephanie L. and Weis, Ulrike and Jochum, Klaus P. and Panthöfer, Martin and Bedzyk, Michael J. and Snyder, G. Jeffrey and Tremel, Wolfgang (2015) Influence of Compensating Defect Formation on the Doping Efficiency and Thermoelectric Properties of Cu_(2-y)Se_(1–x)Br_x. Chemistry of Materials, 27 (20). pp. 7018-7027. ISSN 0897-4756. http://resolver.caltech.edu/CaltechAUTHORS:20151019-095542831

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Abstract

The superionic conductor Cu_(2−δ)Se has been shown to be a promising thermoelectric at higher temperatures because of very low lattice thermal conductivities, attributed to the liquid-like mobility of copper ions in the superionic phase. In this work, we present the potential of copper selenide to achieve a high figure of merit at room temperature, if the intrinsically high hole carrier concentration can be reduced. Using bromine as a dopant, we show that reducing the charge carrier concentration in Cu_(2−δ)Se is in fact possible. Furthermore, we provide profound insight into the complex defect chemistry of bromine doped Cu_(2−δ)Se via various analytical methods and investigate the consequential influences on the thermoelectric transport properties. Here, we show, for the first time, the effect of copper vacancy formation as compensating defects when moving the Fermi level closer to the valence band edge. These compensating defects provide an explanation for the often seen doping inefficiencies in thermoelectrics via defect chemistry and guide further progress in the development of new thermoelectric materials.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1021/acs.chemmater.5b02405DOIArticle
http://pubs.acs.org/doi/10.1021/acs.chemmater.5b02405PublisherArticle
http://pubs.acs.org/doi/suppl/10.1021/acs.chemmater.5b02405PublisherSupporting Information
ORCID:
AuthorORCID
Snyder, G. Jeffrey0000-0003-1414-8682
Alternate Title:Influence of Compensating Defect Formation on the Doping Efficiency and Thermoelectric Properties of Cu2-ySe1–xBrx
Additional Information:© 2015 American Chemical Society. Received: June 24, 2015. Revised: September 24, 2015; Publication Date (Web): September 24, 2015. We acknowledge support from the DFG priority program SPP1386 “Nanostructured Thermoelectrics”. W.G.Z. and G.J.S. acknowledge the EFRC Solid-State Solar-Thermal Energy Conversion Center (S3TEC) award number DE-SC0001299. This work made use of the J. B. Cohen X-ray Diffraction Facility supported by the MRSEC program of the National Science Foundation (DMR-1121262) at the Materials Research Center of Northwestern University. The XPS work was performed in the Keck-II facility of NUANCE Center at Northwestern University. The NUANCE Center is supported by the International Institute for Nanotechnology, MRSEC (NSF DMR-1121262), the Keck Foundation, the State of Illinois, and Northwestern University. T.W.D. and G.J.S. are grateful for the support of the United States Air Force Office of Scientific Research. We thank Riley Hanus for the collection of atom probe data. We also acknowledge Afrora Lulaj and Karoline Herget for their assistance in sample preparation. T.W.D. and K.S.W. contributed equally to this work. The authors declare no competing financial interest.
Funders:
Funding AgencyGrant Number
Deutsche Forschungsgemeinschaft (DFG)SPP1386
Department of Energy (DOE)DE-SC0001299
NSFDMR-1121262
NSFDMR-1121262
W. M. Keck FoundationUNSPECIFIED
State of IllinoisUNSPECIFIED
Northwestern UniversityUNSPECIFIED
Air Force Office of Scientific Research (AFOSR)UNSPECIFIED
Record Number:CaltechAUTHORS:20151019-095542831
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20151019-095542831
Official Citation:Influence of Compensating Defect Formation on the Doping Efficiency and Thermoelectric Properties of Cu2-ySe1–xBrx Tristan W. Day, Kai S. Weldert, Wolfgang G. Zeier, Bor-Rong Chen, Stephanie L. Moffitt, Ulrike Weis, Klaus P. Jochum, Martin Panthöfer, Michael J. Bedzyk, G. Jeffrey Snyder, and Wolfgang Tremel Chemistry of Materials 2015 27 (20), 7018-7027 DOI: 10.1021/acs.chemmater.5b02405
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:61249
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:19 Oct 2015 18:11
Last Modified:30 Nov 2015 17:41

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