Enabling Oxidation Protection and Carrier-Type Switching for Bismuth Telluride Nanoribbons via in Situ Organic Molecule Coating

Journal Article · 11 December 2023 · Nano Letters

DOI: https://doi.org/10.1021/acs.nanolett.3c02000 · OSTI ID:2229489

Park, Jun Beom ^[1]; Wu, Wei ^[2]; Wu, Jason Yingzhi ^[2]; Karkee, Rijan  ^[3]; Kucinski, Theresa Marie ^[1]; Bustillo, Karen C.  ^[4]; Schneider, Matthew M. ^[1]; Strubbe, David A.  ^[5]; Ophus, Colin ^[4]; Pettes, Michael Thompson  ^[1]

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1. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
2. Univ. of Connecticut, Storrs, CT (United States)
3. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Univ. of California, Merced, CA (United States)
4. Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Center for Electron Microscopy (NCEM)
5. Univ. of California, Merced, CA (United States)

Thermoelectric materials with high electrical conductivity and low thermal conductivity (e.g., Bi₂Te₃) can efficiently convert waste heat into electricity; however, in spite of favorable theoretical predictions, individual Bi₂Te₃ nanostructures tend to perform less efficiently than bulk Bi₂Te₃. We report a greater-than-order-of-magnitude enhancement in the thermoelectric properties of suspended Bi₂Te₃ nanoribbons, coated in situ to form a Bi₂Te₃/F₄-TCNQ core–shell nanoribbon without oxidizing the core–shell interface. The shell serves as an oxidation barrier but also directly functions as a strong electron acceptor and p-type carrier donor, switching the majority carriers from a dominant n-type carrier concentration (~10²¹ cm^–3) to a dominant p-type carrier concentration (~10²⁰ cm^–3). Compared to uncoated Bi₂Te₃ nanoribbons, our Bi₂Te₃/F₄-TCNQ core–shell nanoribbon demonstrates an effective chemical potential dramatically shifted toward the valence band (by 300–640 meV), robustly increased Seebeck coefficient (~6× at 250 K), and improved thermoelectric performance (10–20× at 250 K).

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Univ. of California, Merced, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE National Nuclear Security Administration (NNSA); USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities (SUF)
• Grant/Contract Number: AC02-05CH11231; NA0003984; 89233218CNA000001; 20220485MFR; 20190516ECR; 20230014DR
• OSTI ID: 2229489
• Alternate ID(s): OSTI ID: 2246845; OSTI ID: 2267544; OSTI ID: 2350891
• Report Number(s): LA-UR-23-26384
• Journal Information: Nano Letters, Vol. 23, Issue 24; ISSN 1530-6984
• Publisher: American Chemical SocietyCopyright Statement
• Country of Publication: United States
• Language: English