Dual defect system of tellurium antisites and silver interstitials in off-stoichiometric Bi 2 (Te,Se) 3+: Y causing enhanced thermoelectric performance

Cham Kim, David Humberto Lopez, Dong Hwan Kim, Hoyoung Kim

Research output: Contribution to journalArticlepeer-review

29 Scopus citations

Abstract

Enhancement in the thermoelectric performance of n-type Bi 2 (Te,Se) 3 was accomplished by forming a dual defect system composed of Te- and Ag-related defects. Te-rich Bi 2 (Te,Se) 3+y , which has antisite defects generated by an excess of Te, was prepared via a conventional melting process. We devised a one-pot process in which Ag nanoparticles were deposited onto the Te-rich Bi 2 (Te,Se) 3+y as soon as they were chemically synthesized, followed by a sintering compaction; thus, we aimed at selective insertion of Ag atoms into the interstitial sites of the Te-rich Bi 2 (Te,Se) 3+y . The resulting Ag interstitials interact with the Te antisite defects to vary the thermoelectric transport properties of the product. We endeavored to balance the concentration of the defects to maximize the phonon glass electron crystal (PGEC) characteristic of the product, resulting in excellent thermoelectric performance in low temperature regions-we achieved the highest ZT average values, below 150 °C (ZT ave = 1.18 (25-100 °C) and 1.15 (25-150 °C)), ever reported for n-type Bi 2 (Te,Se) 3 materials.

Original languageEnglish
Pages (from-to)791-800
Number of pages10
JournalJournal of Materials Chemistry A
Volume7
Issue number2
DOIs
StatePublished - 2019

Bibliographical note

Publisher Copyright:
© 2019 The Royal Society of Chemistry.

Fingerprint

Dive into the research topics of 'Dual defect system of tellurium antisites and silver interstitials in off-stoichiometric Bi 2 (Te,Se) 3+: Y causing enhanced thermoelectric performance'. Together they form a unique fingerprint.

Cite this