Realizing High Thermoelectric Performance in p-Type SnSe Crystals via Convergence of Multiple Electronic Valence BandsShow others and affiliations
2022 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 14, no 3, p. 4091-4099Article in journal (Refereed) Published
Abstract [en]
SnSe crystals have gained considerable interest for their outstanding thermoelectric performance. Here, we achieve excellent thermoelectric properties in Sn0.99–xPbxZn0.01Se crystals via valence band convergence and point-defect engineering strategies. We demonstrate that Pb and Zn codoping converges the energy offset between multiple valence bands by significantly modifying the band structure, contributing to the enhancement of the Seebeck coefficient. The carrier concentration and electrical conductivity can be optimized, leading to an enhanced power factor. The dual-atom point-defect effect created by the substitution of Pb and Zn in the SnSe lattice introduces strong phonon scattering, significantly reducing the lattice thermal conductivity to as low as 0.284 W m–1 K–1. As a result, a maximum ZT value of 1.9 at 773 K is achieved in Sn0.93Pb0.06Zn0.01Se crystals along the bc-plane direction. This study highlights the crucial role of manipulating multiple electronic valence bands in further improving SnSe thermoelectrics.
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2022. Vol. 14, no 3, p. 4091-4099
Keywords [en]
SnSe crystals, thermoelectric material, band convergence, energy offset, phonon scattering, lattice thermal conductivity
National Category
Condensed Matter Physics
Research subject
Applied Physics
Identifiers
URN: urn:nbn:se:ltu:diva-88801DOI: 10.1021/acsami.1c20549ISI: 000742848600001PubMedID: 35001609Scopus ID: 2-s2.0-85123870723OAI: oai:DiVA.org:ltu-88801DiVA, id: diva2:1628152
Note
Validerad;2022;Nivå 2;2022-02-09 (hanlid);
Funder: National Natural Science Foundation of China (52071182 and U1732153); “Qinglan Project” of the Young and Middle-aged Academic Leader of Jiangsu Province; Fundamental Research Funds for the Central Universities (30921011107)
2022-01-142022-01-142022-04-01Bibliographically approved