Computational and experimental investigation of TmAgTe_2 and XYZ_2 compounds, a new group of thermoelectric materials identified by first-principles high-throughput screening
A new group of thermoelectric materials, trigonal and tetragonal XYZ_2 (X, Y: rare earth or transition metals, Z: group VI elements), the prototype of which is TmAgTe_2, is identified by means of high-throughput computational screening and experiment. Based on density functional theory calculations, this group of materials is predicted to attain high zT (i.e. ∼1.8 for p-type trigonal TmAgTe_2 at 600 K). Among approximately 500 chemical variants of XYZ_2 explored, many candidates with good stability and favorable electronic band structures (with high band degeneracy leading to high power factor) are presented. Trigonal TmAgTe_2 has been synthesized and exhibits an extremely low measured thermal conductivity of 0.2–0.3 W m^(−1) K^(−1) for T > 600 K. The zT value achieved thus far for p-type trigonal TmAgTe_2 is approximately 0.35, and is limited by a low hole concentration (∼10^(17) cm^(−3) at room temperature). Defect calculations indicate that Tm_(Ag) antisite defects are very likely to form and act as hole killers. Further defect engineering to reduce such XY antisites is deemed important to optimize the zT value of the p-type TmAgTe_2.
© 2015 The Royal Society of Chemistry. Received 20th May 2015, Accepted 3rd August 2015, First published online 13 Aug 2015. This article is part of themed collection: 2015 Journal of Materials Chemistry C Hot Papers and The Chemistry of Thermoelectric Materials. This work was intellectually led by the Materials Project which is supported by the Department of Energy Basic Energy Sciences program under Grant No. EDCBEE, DOE Contract DE-AC02-05CH11231. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy. U.A. acknowledges the financial assistance of The Scientific and Technological Research Council of Turkey. J.-H.P. acknowledges the Dalhousie Research in Energy, Advanced Materials and Sustainability (DREAMS) NSERC CREATE program. M.A.W. acknowledges the support of NSERC, and Dalhousie University's Institute for Research in Materials and its Facilities for Materials Characterization. G.H. acknowledges the F.R.S.-FNRS and the European Union Marie Curie Career Integration (CIG) grant HTforTCOs PCIG11-GA-2012-321988 for financial support. Z.M.G. acknowledges the Molecular Materials Research Center (MMRC) at Caltech in the Beckman Institute where optical measurements in this work were performed.
Correction: Computational and experimental investigation of TmAgTe2 and XYZ2 compounds, a new group of thermoelectric materials identified by first-principles high-throughput screening Hong Zhu, Geoffroy Hautier, Umut Aydemir, Zachary M. Gibbs, Guodong Li, Saurabh Bajaj, Jan-Hendrik Pöhls, Danny Broberg, Wei Chen, Anubhav Jain, Mary Anne White, Mark Asta, G. Jeffrey Snyder, Kristin Persson and Gerbrand Ceder J. Mater. Chem. C, 2016,4, 4331-4331 DOI: 10.1039/C6TC90077A
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Erratum - c6tc90077a.pdf