Jinfeng Dong, Yukun Liu, Jue Liu, Lei Hu, Yilin Jiang, Xian Yi Tan, Yuansheng Shi, Dongwang Yang, Kivanc Saglik, Ady Suwardi, Qian Li, Jing-Feng Li, Vinayak P. Dravid, Qingyu Yan, Mercouri G. Kanatzidis
{"title":"Relating Local Structure to Thermoelectric Properties in Pb1–xGexBi2Te4","authors":"Jinfeng Dong, Yukun Liu, Jue Liu, Lei Hu, Yilin Jiang, Xian Yi Tan, Yuansheng Shi, Dongwang Yang, Kivanc Saglik, Ady Suwardi, Qian Li, Jing-Feng Li, Vinayak P. Dravid, Qingyu Yan, Mercouri G. Kanatzidis","doi":"10.1021/acs.chemmater.4c02649","DOIUrl":null,"url":null,"abstract":"Layered compounds have garnered widespread interest owing to their nontrivial physical properties, particularly their potential as thermoelectric materials. We systematically investigated PbBi<sub>2</sub>Te<sub>4</sub>, a compound derived from Bi<sub>2</sub>Te<sub>3</sub> and PbTe. Synchrotron X-ray diffraction and transmission electron microscopy revealed that PbBi<sub>2</sub>Te<sub>4</sub> adopts and maintains the <i>R</i>3̅<i>m</i> phase from 300 to 723 K, without any phase transition. Moreover, neutron pair distribution function analysis confirmed that the short-range local structure was consistent with the high-symmetry <i>R</i>3̅<i>m</i> structure. PbBi<sub>2</sub>Te<sub>4</sub> exhibits a negative Seebeck coefficient, indicating electron-dominated transport. It has a low lattice thermal conductivity (ca. 0.6 Wm<sup>–1</sup>K<sup>–1</sup>) and a ZT value of 0.4 at 573 K. The effects of GeBi<sub>2</sub>Te<sub>4</sub> alloying in PbBi<sub>2</sub>Te<sub>4</sub> (Pb<sub>1–<i>x</i></sub>Ge<sub><i>x</i></sub>Bi<sub>2</sub>Te<sub>4</sub>, where <i>x</i> ranges from 0.0 to 0.6) were also investigated. Due to alloying-induced point defect scattering and the off-centering effects of Ge<sup>2+</sup>, the room-temperature lattice thermal conductivity decreased to 0.55 Wm<sup>–1</sup>K<sup>–1</sup> when <i>x</i> = 0.5. Combined with a maintained weighted mobility (ca. 60 cm<sup>2</sup>V<sup>–1</sup>s<sup>–2</sup>), the room-temperature ZT increased to 0.28. This value could further increase to 0.65 with a reduction in lattice thermal conductivity to its lower-limit value. A high ZT of 1.0 is also predicted for pristine PbBi<sub>2</sub>Te<sub>4</sub> at 473 K, demonstrating its potential as a near-room-temperature thermoelectric system.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":null,"pages":null},"PeriodicalIF":7.2000,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemistry of Materials","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1021/acs.chemmater.4c02649","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Layered compounds have garnered widespread interest owing to their nontrivial physical properties, particularly their potential as thermoelectric materials. We systematically investigated PbBi2Te4, a compound derived from Bi2Te3 and PbTe. Synchrotron X-ray diffraction and transmission electron microscopy revealed that PbBi2Te4 adopts and maintains the R3̅m phase from 300 to 723 K, without any phase transition. Moreover, neutron pair distribution function analysis confirmed that the short-range local structure was consistent with the high-symmetry R3̅m structure. PbBi2Te4 exhibits a negative Seebeck coefficient, indicating electron-dominated transport. It has a low lattice thermal conductivity (ca. 0.6 Wm–1K–1) and a ZT value of 0.4 at 573 K. The effects of GeBi2Te4 alloying in PbBi2Te4 (Pb1–xGexBi2Te4, where x ranges from 0.0 to 0.6) were also investigated. Due to alloying-induced point defect scattering and the off-centering effects of Ge2+, the room-temperature lattice thermal conductivity decreased to 0.55 Wm–1K–1 when x = 0.5. Combined with a maintained weighted mobility (ca. 60 cm2V–1s–2), the room-temperature ZT increased to 0.28. This value could further increase to 0.65 with a reduction in lattice thermal conductivity to its lower-limit value. A high ZT of 1.0 is also predicted for pristine PbBi2Te4 at 473 K, demonstrating its potential as a near-room-temperature thermoelectric system.
期刊介绍:
The journal Chemistry of Materials focuses on publishing original research at the intersection of materials science and chemistry. The studies published in the journal involve chemistry as a prominent component and explore topics such as the design, synthesis, characterization, processing, understanding, and application of functional or potentially functional materials. The journal covers various areas of interest, including inorganic and organic solid-state chemistry, nanomaterials, biomaterials, thin films and polymers, and composite/hybrid materials. The journal particularly seeks papers that highlight the creation or development of innovative materials with novel optical, electrical, magnetic, catalytic, or mechanical properties. It is essential that manuscripts on these topics have a primary focus on the chemistry of materials and represent a significant advancement compared to prior research. Before external reviews are sought, submitted manuscripts undergo a review process by a minimum of two editors to ensure their appropriateness for the journal and the presence of sufficient evidence of a significant advance that will be of broad interest to the materials chemistry community.