Highly charged interface trap states in PbS1−x govern electro-thermal transport
Author
Yazdani, SajadHuan, Tran Doan
Liu, Yufei
Kashfi-Sadabad, Raana
Montaño, Raul David
He, Jian
Pettes, Michael Thompson
Affiliation
Univ Arizona, Dept Aerosp & Mech EngnIssue Date
2019-07
Metadata
Show full item recordPublisher
AMER INST PHYSICSCitation
Yazdani, Sajad & Doan Huan, Tran & Liu, Yufei & Kashfi Sadabad, Raana & David Montaño, Raul & He, Jian & Thompson Pettes, Michael. (2019). Highly charged interface trap states in PbS 1− x govern electro-thermal transport. APL Materials. 7. 071105. 10.1063/1.5096786.Journal
APL MATERIALSRights
Copyright © 2019 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
This work describes our discovery of the dominant role of highly charged interfaces on the electrothermal transport properties of PbS, along with a method to reduce the barrier potential for charge carriers by an order of magnitude. High temperature thermoelectrics such as PbS are inevitably exposed to elevated temperatures during postsynthesis treatment as well as operation. However, we observed that as the material was heated, large concentrations of sulfur vacancy (VS..) sites were formed at temperatures as low as 266 degrees C. This loss of sulfur doped the PbS n-type and increased the carrier concentration, where these excess electrons were trapped and immobilized at interfacial defect sites in polycrystalline PbS with an abundance of grain boundaries. Sulfur deficient PbS0.81 exhibited a large barrier potential for charge carriers of 0.352 eV, whereas annealing the material under a sulfur-rich environment prevented VS.. formation and lowered the barrier by an order of magnitude to 0.046 eV. Through ab initio calculations, the formation of VS.. was found to be more favorable on the surface compared to the bulk of the material with a 1.72 times lower formation energy barrier. These observations underline the importance of controlling interface-vacancy effects in the preparation of bulk materials comprised of nanoscale constituents.Note
Open access journalISSN
2166-532XVersion
Final published versionSponsors
U. S. National Science Foundation [CAREER-1553987, REU-1560098]; UConn Research Foundation [PD17-0137]; U.S. Department of Energy Office of Science [89233218CNA000001]; GE Graduate Fellowship for Innovation; XSEDE through the computational resource allocation [TG-DMR170031]ae974a485f413a2113503eed53cd6c53
10.1063/1.5096786
Scopus Count
Collections
Except where otherwise noted, this item's license is described as Copyright © 2019 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).