Enhancement of Thermoelectric Performance for n-Type PbS through Synergy of Gap State and Fermi Level Pinning

Zhong Zhen Luo, Shiqiang Hao, Songting Cai, Trevor P. Bailey, Gangjian Tan, Yubo Luo, Ioannis Spanopoulos, Ctirad Uher, Chris Wolverton, Vinayak P. Dravid, Qingyu Yan, Mercouri G. Kanatzidis

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

We report that Ga-doped and Ga-In-codoped n-type PbS samples show excellent thermoelectric performance in the intermediate temperature range. First-principles electronic structure calculations reveal that Ga doping can cause Fermi level pinning in PbS by introducing a gap state between the conduction and valence bands. Furthermore, Ga-In codoping introduces an extra conduction band. These added electronic features lead to high electron mobilities up to μH ∼ 630 cm2 V-1 s-1 for n of 1.67 × 1019 cm-3 and significantly enhanced Seebeck coefficients in PbS. Consequently, we obtained a maximum power factor of ∼32 μW cm-1 K-2 at 300 K for Pb0.9875Ga0.0125S, which is the highest reported for PbS-based systems giving a room-temperature figure of merit, ZT, of ∼0.35 and ∼0.82 at 923 K. For the codoped Pb0.9865Ga0.0125In0.001S, the maximum ZT rises to ∼1.0 at 923 K and achieves a record-high average ZT (ZTavg) of ∼0.74 in the temperature range of 400-923 K.

Original languageEnglish
Pages (from-to)6403-6412
Number of pages10
JournalJournal of the American Chemical Society
Volume141
Issue number15
DOIs
Publication statusPublished - Apr 17 2019

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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    Luo, Z. Z., Hao, S., Cai, S., Bailey, T. P., Tan, G., Luo, Y., Spanopoulos, I., Uher, C., Wolverton, C., Dravid, V. P., Yan, Q., & Kanatzidis, M. G. (2019). Enhancement of Thermoelectric Performance for n-Type PbS through Synergy of Gap State and Fermi Level Pinning. Journal of the American Chemical Society, 141(15), 6403-6412. https://doi.org/10.1021/jacs.9b01889