High Thermoelectric Performance of AgSb1-x Pbx Se2 Prepared by Fast Nonequilibrium Synthesis.

Journal Article

AgSbSe2 is a typical member of cubic I-V-VI2 semiconductors, which are known for their extremely low lattice thermal conductivity (κl ). However, the low electrical conductivity of AgSbSe2 , below ∼10 S cm-1 at room temperature, has hindered its thermoelectric performance. In this work, single-phase AgSbSe2 bulk samples with much higher electrical conductivity were synthesized via self-propagating high-temperature synthesis (SHS) combined with spark plasma sintering (SPS) for the first time. Pb doping through the nonequilibrium process further increases the electrical conductivity to >100 S cm-1 . Furthermore, continuously increased effective mass m d * can be achieved upon Pb doping because of the multiple degenerate valence bands of AgSbSe2 and the energy-filtering effect induced by in situ -formed nanodots. The simultaneous enhancement of both the electrical conductivity and Seebeck coefficient contributes to an unprecedentedly high average power factor of 6.75 μW cm-1 K-2 . Meanwhile, the introduced dense grain boundaries and point defects enhance the phonon scattering and consequently suppress κl , yielding a high ZT value of 1.2 at 723 K in AgSb0.94 Pb0.06 Se2 . This study opens a new avenue for rapid, low-cost, large-scale production of AgSbSe2 -based materials and demonstrates that Pb-doped AgSbSe2 prepared via the SHS-SPS method is a promising candidate for thermoelectric applications.

Full Text

Duke Authors

Cited Authors

  • Tan, X; Ding, J; Luo, H; Delaire, O; Yang, J; Zhou, Z; Lan, J-L; Lin, Y-H; Nan, C-W

Published Date

  • September 2, 2020

Published In

Volume / Issue

  • 12 / 37

Start / End Page

  • 41333 - 41341

PubMed ID

  • 32820890

Pubmed Central ID

  • 32820890

Electronic International Standard Serial Number (EISSN)

  • 1944-8252

International Standard Serial Number (ISSN)

  • 1944-8244

Digital Object Identifier (DOI)

  • 10.1021/acsami.0c10508

Language

  • eng