Boron‐Mediated Grain Boundary Engineering Enables Simultaneous Improvement of Thermoelectric and Mechanical Properties in N‐Type Bi2Te3

Small, vol. 17, pp. e2104067

Abstract

Abstract Powder metallurgy introduces small structures of high‐density grain boundaries into Bi2Te3‐based alloys, which promises to enhance their mechanical and thermoelectric performance. However, due to the strong donor‐like effect induced by the increased surface, Te vacancies form in the powder‐metallurgy process. Hence, the as‐sintered n‐type Bi2Te3‐based alloys show a lower figure of merit (ZT) value than their p‐type counterparts and the commercial zone‐melted (ZM) ingots. Here, boron is added to one‐step‐sintered n‐type Bi2Te3‐based alloys to inhibit grain growth and to suppress the donor‐like effect, simultaneously improving the mechanical and thermoelectric (TE) performance. Due to the alleviated donor‐like effect and the carrier mobility maintained in our n‐type Bi2Te2.7Se0.3 alloys upon the addition of boron, the maximum and average ZT values within 298–473 K can be enhanced to 1.03 and 0.91, respectively, which are even slightly higher than that of n‐type ZM ingots. Moreover, the addition of boron greatly improves the mechanical strength such as Vickers hardness and compressive strength due to the synergetic effects of Hall‐Petch grain‐boundary strengthening and boron dispersion strengthening. This facile and cost‐effective grain boundary engineering by adding boron facilitates the practical application of Bi2Te3‐based alloys and can also be popularized in other thermoelectric materials.

Authors 12

1. Chaohua Zhang corresponding

   Shenzhen University · Guangdong Research Center for Interfacial Engineering of Functional Materials

   Affiliation as printed

   College of Materials Science and Engineering Shenzhen Key Laboratory of Special Functional Materials Shenzhen Engineering Laboratory for Advanced Technology of Ceramics Guangdong Research Center for Interfacial Engineering of Functional Materials Institute of Deep Underground Sciences and Green Energy Shenzhen University Shenzhen 518060 P. R. China

   College of Materials Science and Engineering, Shenzhen Key Laboratory of Special Functional Materials, Shenzhen Engineering Laboratory for Advanced Technology of Ceramics, Guangdong Research Center for Interfacial Engineering of Functional Materials, Institute of Deep Underground Sciences and Green Energy, Shenzhen University, Shenzhen, 518060 P. R. China

2. Xingjin Geng

   Shenzhen University · Guangdong Research Center for Interfacial Engineering of Functional Materials

   Affiliation as printed

   College of Materials Science and Engineering Shenzhen Key Laboratory of Special Functional Materials Shenzhen Engineering Laboratory for Advanced Technology of Ceramics Guangdong Research Center for Interfacial Engineering of Functional Materials Institute of Deep Underground Sciences and Green Energy Shenzhen University Shenzhen 518060 P. R. China

   College of Materials Science and Engineering, Shenzhen Key Laboratory of Special Functional Materials, Shenzhen Engineering Laboratory for Advanced Technology of Ceramics, Guangdong Research Center for Interfacial Engineering of Functional Materials, Institute of Deep Underground Sciences and Green Energy, Shenzhen University, Shenzhen, 518060 P. R. China

3. Bin Chen

   Shenzhen University · Guangdong Research Center for Interfacial Engineering of Functional Materials

   Affiliation as printed

   College of Materials Science and Engineering Shenzhen Key Laboratory of Special Functional Materials Shenzhen Engineering Laboratory for Advanced Technology of Ceramics Guangdong Research Center for Interfacial Engineering of Functional Materials Institute of Deep Underground Sciences and Green Energy Shenzhen University Shenzhen 518060 P. R. China

   College of Materials Science and Engineering, Shenzhen Key Laboratory of Special Functional Materials, Shenzhen Engineering Laboratory for Advanced Technology of Ceramics, Guangdong Research Center for Interfacial Engineering of Functional Materials, Institute of Deep Underground Sciences and Green Energy, Shenzhen University, Shenzhen, 518060 P. R. China

4. Junqin Li

   Shenzhen University · Guangdong Research Center for Interfacial Engineering of Functional Materials

   Affiliation as printed

   College of Materials Science and Engineering Shenzhen Key Laboratory of Special Functional Materials Shenzhen Engineering Laboratory for Advanced Technology of Ceramics Guangdong Research Center for Interfacial Engineering of Functional Materials Institute of Deep Underground Sciences and Green Energy Shenzhen University Shenzhen 518060 P. R. China

   College of Materials Science and Engineering, Shenzhen Key Laboratory of Special Functional Materials, Shenzhen Engineering Laboratory for Advanced Technology of Ceramics, Guangdong Research Center for Interfacial Engineering of Functional Materials, Institute of Deep Underground Sciences and Green Energy, Shenzhen University, Shenzhen, 518060 P. R. China

5. Alexander Meledin Aachen Central Facility for Electron Microscopy

   RWTH Aachen University

   Affiliation as printed

   Central Facility for Electron Microscopy (GFE) RWTH Aachen University Ahornstr. 55 D‐52074 Aachen Germany

   Central Facility for Electron Microscopy (GFE), RWTH Aachen University, Ahornstr. 55, D-52074 Aachen, Germany

6. Lipeng Hu

   Shenzhen University · Guangdong Research Center for Interfacial Engineering of Functional Materials

   Affiliation as printed

   College of Materials Science and Engineering Shenzhen Key Laboratory of Special Functional Materials Shenzhen Engineering Laboratory for Advanced Technology of Ceramics Guangdong Research Center for Interfacial Engineering of Functional Materials Institute of Deep Underground Sciences and Green Energy Shenzhen University Shenzhen 518060 P. R. China

   College of Materials Science and Engineering, Shenzhen Key Laboratory of Special Functional Materials, Shenzhen Engineering Laboratory for Advanced Technology of Ceramics, Guangdong Research Center for Interfacial Engineering of Functional Materials, Institute of Deep Underground Sciences and Green Energy, Shenzhen University, Shenzhen, 518060 P. R. China

7. Fusheng Liu

   Shenzhen University · Guangdong Research Center for Interfacial Engineering of Functional Materials

   Affiliation as printed

   College of Materials Science and Engineering Shenzhen Key Laboratory of Special Functional Materials Shenzhen Engineering Laboratory for Advanced Technology of Ceramics Guangdong Research Center for Interfacial Engineering of Functional Materials Institute of Deep Underground Sciences and Green Energy Shenzhen University Shenzhen 518060 P. R. China

   College of Materials Science and Engineering, Shenzhen Key Laboratory of Special Functional Materials, Shenzhen Engineering Laboratory for Advanced Technology of Ceramics, Guangdong Research Center for Interfacial Engineering of Functional Materials, Institute of Deep Underground Sciences and Green Energy, Shenzhen University, Shenzhen, 518060 P. R. China

8. Jigui Shi

   Shenzhen University · Guangdong Research Center for Interfacial Engineering of Functional Materials

   Affiliation as printed

   College of Materials Science and Engineering Shenzhen Key Laboratory of Special Functional Materials Shenzhen Engineering Laboratory for Advanced Technology of Ceramics Guangdong Research Center for Interfacial Engineering of Functional Materials Institute of Deep Underground Sciences and Green Energy Shenzhen University Shenzhen 518060 P. R. China

   College of Materials Science and Engineering, Shenzhen Key Laboratory of Special Functional Materials, Shenzhen Engineering Laboratory for Advanced Technology of Ceramics, Guangdong Research Center for Interfacial Engineering of Functional Materials, Institute of Deep Underground Sciences and Green Energy, Shenzhen University, Shenzhen, 518060 P. R. China

9. Joachim Mayer Aachen Central Facility for Electron Microscopy

   Forschungszentrum Jülich · Ernst Ruska Centre · RWTH Aachen University

   Affiliation as printed

   Central Facility for Electron Microscopy (GFE) RWTH Aachen University Ahornstr. 55 D‐52074 Aachen Germany

   Ernst Ruska‐Centre for Microscopy and Spectroscopy with Electrons (ER‐C 2) Forschungszentrum Jülich D‐52425 Jülich Germany

   Central Facility for Electron Microscopy (GFE), RWTH Aachen University, Ahornstr. 55, D-52074 Aachen, Germany

10. Matthias Wuttig Aachen Institute of Physics IA

    Forschungszentrum Jülich · RWTH Aachen University

    Affiliation as printed

    Institute of Physics IA RWTH Aachen University 52056 Aachen Germany

    PGI 10 (Green IT) Forschungszentrum Jülich GmbH 52428 Jülich Germany

    Institute of Physics IA, RWTH Aachen University, 52056 Aachen, Germany

11. Oana Cojocaru‐Mirédin Aachen Institute of Physics IA

    RWTH Aachen University

    Affiliation as printed

    Institute of Physics IA RWTH Aachen University 52056 Aachen Germany

    Institute of Physics IA, RWTH Aachen University, 52056 Aachen, Germany

12. Yuan Yu corresponding Aachen Institute of Physics IA

    RWTH Aachen University

    Affiliation as printed

    Institute of Physics IA RWTH Aachen University 52056 Aachen Germany

    Institute of Physics IA, RWTH Aachen University, 52056 Aachen, Germany