Journal Article

FZJ-2019-06550

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png High-Performance n-Type PbSe–Cu 2 Se Thermoelectrics through Conduction Band Engineering and Phonon Softening

Zhou, C. ; Yu, Y. ; Lee, Y. K. ; Cojocaru-Mirédin, O. ; Yoo, B. ; Cho, S.-P. ; Im, J. ; Wuttig, M.FZJ* ; Hyeon, T. ; Chung, I. (Corresponding author)

2018
American Chemical Society Washington, DC

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Please use a persistent id in citations: doi:10.1021/jacs.8b10448

Abstract: From a structural and economic perspective, tellurium-free PbSe can be an attractive alternative to its more expensive isostructural analogue of PbTe for intermediate temperature power generation. Here we report that PbSe0.998Br0.002-2%Cu2Se exhibits record high peak ZT 1.8 at 723 K and average ZT 1.1 between 300 and 823 K to date for all previously reported n- and p-type PbSe-based materials as well as tellurium-free n-type polycrystalline materials. These even rival the highest reported values for n-type PbTe-based materials. Cu2Se doping not only enhance charge transport properties but also depress thermal conductivity of n-type PbSe. It flattens the edge of the conduction band of PbSe, increases the effective mass of charge carriers, and enlarges the energy band gap, which collectively improve the Seebeck coefficient markedly. This is the first example of manipulating the electronic conduction band to enhance the thermoelectric properties of n-type PbSe. Concurrently, Cu2Se increases the carrier concentration with nearly no loss in carrier mobility, even increasing the electrical conductivity above ∼423 K. The resulting power factor is ultrahigh, reaching ∼21–26 μW cm–1 K–2 over a wide range of temperature from ∼423 to 723 K. Cu2Se doping substantially reduces the lattice thermal conductivity to ∼0.4 W m–1 K–1 at 773 K, approaching its theoretical amorphous limit. According to first-principles calculations, the achieved ultralow value can be attributed to remarkable acoustic phonon softening at the low-frequency region.

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Contributing Institute(s):

1. JARA Institut Green IT (PGI-10)

Research Program(s):

1. 521 - Controlling Electron Charge-Based Phenomena (POF3-521) (POF3-521)

Appears in the scientific report 2019

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Database coverage:
; BIOSIS Previews ; Clarivate Analytics Master Journal List ; Current Contents - Life Sciences ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF >= 10 ; JCR ; NCBI Molecular Biology Database ; Nationallizenz ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Web of Science Core Collection

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