title: High thermoelectric performance by resonant dopant indium in nanostructured SnTe.
abstract: From an environmental perspective, lead-free SnTe would be preferable for solid-state waste heat recovery if its thermoelectric figure-of-merit could be brought close to that of the lead-containing chalcogenides. In this work, we studied the thermoelectric properties of nanostructured SnTe with different dopants, and found indium-doped SnTe showed extraordinarily large Seebeck coefficients that cannot be explained properly by the conventional two-valence band model. We attributed this enhancement of Seebeck coefficients to resonant levels created by the indium impurities inside the valence band, supported by the first-principles simulations. This, together with the lower thermal conductivity resulting from the decreased grain size by ball milling and hot pressing, improved both the peak and average nondimensional figure-of-merit (ZT) significantly. A peak ZT of ∼1.1 was obtained in 0.25 atom % In-doped SnTe at about 873 K.
authors.affiliation: Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204, USA.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.forename: Bolin
authors.initials: B
authors.lastname: Liao
authors.forename: Yucheng
authors.initials: Y
authors.lastname: Lan
authors.forename: Kevin
authors.initials: K
authors.lastname: Lukas
authors.forename: Weishu
authors.initials: W
authors.lastname: Liu
authors.forename: Keivan
authors.initials: K
authors.lastname: Esfarjani
authors.forename: Cyril
authors.initials: C
authors.lastname: Opeil
authors.forename: David
authors.initials: D
authors.lastname: Broido
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.forename: Zhifeng
authors.initials: Z
authors.lastname: Ren
mesh_terms: D004553:Electric Conductivity; D007495:Iridium / Q000737:chemistry*; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008956:Models, Chemical; D049329:Nanostructures / Q000737:chemistry*; D013691:Tellurium / Q000737:chemistry*; D013696:Temperature; D017971:Tin Compounds / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D017971:Tin Compounds; D007495:Iridium; D013691:Tellurium
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