无机材料学报 ›› 2023, Vol. 38 ›› Issue (7): 807-814.DOI: 10.15541/jim20220751 CSTR: 32189.14.10.15541/jim20220751

所属专题: 【能源环境】热电材料(202409)

• 研究论文 • 上一篇    下一篇

稳定立方相结构的n型无铅AgBiSe2基热电材料

王姝灵1(), 蒋蒙1, 王连军1(), 江莞1,2   

  1. 1.东华大学 材料科学与工程学院, 纤维材料改性国家重点实验室, 上海 201620
    2.东华大学 功能材料研究中心, 上海 201620
  • 收稿日期:2022-12-14 修回日期:2023-01-31 出版日期:2023-03-10 网络出版日期:2023-03-10
  • 通讯作者: 王连军, 教授. E-mail: wanglj@dhu.edu.cn
  • 作者简介:王姝灵(1999-), 女, 硕士研究生. E-mail: Wangshuling0120@163.com
  • 基金资助:
    国家自然科学基金(51871053);国家自然科学基金(52174343)

n-Type Pb-free AgBiSe2 Based Thermoelectric Materials with Stable Cubic Phase Structure

WANG Shuling1(), JIANG Meng1, WANG Lianjun1(), JIANG Wan1,2   

  1. 1. State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620
    2. China Institute of Functional Materials, Donghua University, Shanghai 201620, China
  • Received:2022-12-14 Revised:2023-01-31 Published:2023-03-10 Online:2023-03-10
  • Contact: WANG Lianjun, professor. E-mail: wanglj@dhu.edu.cn
  • About author:WANG Shuling (1999-), female, Master candidate. E-mail: Wangshuling0120@163.com
  • Supported by:
    National Natural Science Foundation of China(51871053);National Natural Science Foundation of China(52174343)

摘要:

n型AgBiSe2基化合物的晶格热导率低, 是一种很有潜力的高性能热电材料。然而, 本征AgBiSe2化合物在300~700 K之间存在两次相变, 使其应用受限。因此, 获得具有稳定结构的AgBiSe2基化合物, 并优化热电性能至关重要。本研究选择无铅的IV-VI族化合物SnTe与AgBiSe2进行合金化, 制备了(AgBiSe2)1-x(SnTe)x (x=0.10~0.30)化合物。引入SnTe降低了AgBiSe2立方相的相变温度, 还有效抑制其发生可逆相变, 得到了稳定的立方相(AgBiSe2)0.75(SnTe)0.25材料。SnTe引起晶格中原子高度无序分布, 导致室温下晶格热导率从0.76 W·m-1·K-1(x=0.10)降低到0.51 W·m-1·K-1(x=0.30)。进一步Ag位掺杂Nb元素, 可以提升载流子浓度, 增加该体系((Ag1-yNbyBiSe2)0.75(SnTe)0.25化合物)的有效质量, 大幅度提升电性能。室温下电导率由77.7 S·cm-1(基体)增大到158.1 S·cm-1 (y=0.02)。同时, 材料中的杂质点缺陷也逐步增加, 高温下缺陷散射进一步降低晶格热导率。在700 K时, 晶格热导率由0.56 W·m-1·K-1(未掺杂)降低至0.43 W·m-1·K-1 (y=0.04), 最终获得了立方相结构稳定的(Ag0.98Nb0.02BiSe2)0.75(SnTe)0.25材料, 650 K的ZT达到0.32。上述研究结果表明, (AgBiSe2)0.75(SnTe)0.25化合物是一种具有低晶格热导率和稳定立方相结构的n型热电材料。本研究为高性能相变热电材料的晶体结构调控提出了新解决方案, 有助于进一步推动其应用发展。

关键词: AgBiSe2基化合物, 晶格热导率, 立方相

Abstract:

n-Type AgBiSe2-based compounds are considered as promising high-performance thermoelectric (TE) materials due to the low lattice thermal conductivity. However, their two phase transitions between 300 and 700 K limits their applications. Therefore, it is crucial to obtain AgBiSe2-based compounds with stable structures and optimized TE properties. In this work, the Pb-free group IV-VI compound SnTe is selected for alloying with AgBiSe2. Introduction of SnTe not only reduces the cubic phase transition temperature, but also effectively suppresses the reversible phase transition of AgBiSe2. At room temperature, reduction of the lattice thermal conductivity from 0.76 to 0.51 W·m-1·K-1 results from highly disordered distribution of atoms. Furthermore, Nb dopant to replace Ag, significantly improves carrier concentration of AgBiSe2-based compounds, which promotes the effective mass and increases the electrical conductivity from 77.7 S·cm-1 to 158.1 S·cm-1 at room temperature. Meanwhile, the defect scattering at high temperature is enhanced with the increase of impurity point defects, leading to the lattice thermal conductivity reduced. At 700 K, the lattice thermal conductivity is reduced from 0.56 to 0.43 W·m-1·K-1, obtaining stable cubic phase compound (Ag0.98Nb0.02BiSe2)0.75(SnTe)0.25 with a ZT of 0.32 at 650 K. These results indicate that the (AgBiSe2)0.75(SnTe)0.25 compound is a promising n-type TE compound with low lattice thermal conductivity and a stable cubic structure. Such efforts provide a scheme for the crystal structure regulation of high-performance TE materials with phase transition and promotion of its application.

Key words: AgBiSe2-based compound, lattice thermal conductivity, cubic structure

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