Synergetic Enhancement of Thermoelectric Performance by Selective Charge Anderson Localization-Delocalization Transition in n-Type Bi-Doped PbTe/Ag2Te Nanocomposite

Lee MH, Yun JH, Kim G, Lee JE, Park SD, Reith H, Schierning G, Nielsch K, Ko W, Li AP, Rhyee JS (2019)

Publication Type: Journal article

Publication year: 2019

Journal

ACS nano American Chemical Society

DOI: 10.1021/acsnano.8b08579

Abstract

Considerable efforts have been devoted to enhancing thermoelectric performance, by employing phonon scattering from nanostructural architecture, and material design using phonon-glass and electron-crystal concepts. The nanostructural approach helps to lower thermal conductivity but has limited effect on the power factor. Here, we demonstrate selective charge Anderson localization as a route to maximize the Seebeck coefficient while simultaneously preserving high electrical conductivity and lowering the lattice thermal conductivity. We confirm the viability of interface potential modification in an n-type Bi-doped PbTe/Ag 2 Te nanocomposite and the resulting enhancement in thermoelectric figure-of-merit ZT. The introduction of random potentials via Ag 2 Te nanoparticle distribution using extrinsic phase mixing was determined using scanning tunneling spectroscopy measurements. When the Ag 2 Te undergoes a structural phase transition (T > 420 K) from monoclinic β-Ag 2 Te to cubic α-Ag 2 Te, the band gap in the α-Ag 2 Te increases due to the p-d hybridization. This results in a decrease in the potential barrier height, which gives rise to partial delocalization of the electrons, while wave packets of the holes are still in a localized state. Using this strategic approach, we achieved an exceptionally high thermoelectric figure-of-merit in n-type PbTe materials, a ZT greater than 2.0, suitable for waste heat power generation.

Involved external institutions

Kyung Hee University KR Korea, Republic of (KR) Korea Electrotechnology Research Institute / 한국전기연구원 (KERI) KR Korea, Republic of (KR) Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden e.V. (IFW) / Leibniz Institute for Solid State and Materials Research Dresden DE Germany (DE) Oak Ridge National Laboratory US United States (USA) (US)

How to cite

APA:

Lee, M.H., Yun, J.H., Kim, G., Lee, J.E., Park, S.-D., Reith, H.,... Rhyee, J.-S. (2019). Synergetic Enhancement of Thermoelectric Performance by Selective Charge Anderson Localization-Delocalization Transition in n-Type Bi-Doped PbTe/Ag2Te Nanocomposite. ACS nano. https://doi.org/10.1021/acsnano.8b08579

MLA:

Lee, Min Ho, et al. "Synergetic Enhancement of Thermoelectric Performance by Selective Charge Anderson Localization-Delocalization Transition in n-Type Bi-Doped PbTe/Ag2Te Nanocomposite." ACS nano (2019).

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