Journal of Inorganic Materials ›› 2024, Vol. 39 ›› Issue (11): 1283-1291.DOI: 10.15541/jim20240165

Special Issue: 【能源环境】热电材料(202409)

• RESEARCH LETTER • Previous Articles     Next Articles

Single- and Two-band Transport Properties Crossover in Bi2Te3 Based Thermoelectrics

MENG Yuting(), WANG Xuemei, ZHANG Shuxian, CHEN Zhiwei(), PEI Yanzhong()   

  1. Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Tongji University, Shanghai 201804, China
  • Received:2024-04-02 Revised:2024-05-20 Published:2024-11-20 Online:2024-06-13
  • Contact: PEI Yanzhong, professor. E-mail: yanzhong@tongji.edu.cn;
    CHEN Zhiwei, associate professor. E-mail: 14czw@tongji.edu.cn
  • About author:MENG Yuting (1999-), female, Master candidate. E-mail: 2130605@tongji.edu.cn
  • Supported by:
    National Natural Science Foundation of China(T2125008);National Natural Science Foundation of China(92263108);National Natural Science Foundation of China(92163203);National Natural Science Foundation of China(52102292);National Natural Science Foundation of China(52003198);Shanghai Rising-Star Program(23QA1409300);Innovation Program of Shanghai Municipal Education Commission(2021-01-07-00-07-E00096)

Abstract:

Based on Peltier effect, Bi2Te3-based alloy is widely used in commercial solid-state refrigeration at room temperature. The mainstream strategies for enhancing room-temperature thermoelectric performance in Bi2Te3 focus on band and microstructure engineering. However, a clear understanding of the modulation of band structure and scattering through such engineering remains still challenging, because the minority carriers compensate partially the overall transport properties for the narrow-gap Bi2Te3 at room temperature (known as the bipolar effect). The purpose of this work is to model the transport properties near and far away from the bipolar effect region for Bi2Te3-based thermoelectric material by a two-band model taking contributions of both majority and minority carriers into account. This is endowed by shifting the Fermi level from the conduction band to the valence band during the modeling. A large amount of data of Bi2Te3-based materials is collected from various studies for the comparison between experimental and predicted properties. The fundamental parameters, such as the density of states effective masses and deformation potential coefficients, of Bi2Te3-based materials are quantified. The analysis can help find out the impact factors (e.g. the mobility ratio between conduction and valence bands) for the improvement of thermoelectric properties for Bi2Te3-based alloys. This work provides a convenient tool for analyzing and predicting the transport performance even in the presence of bipolar effect, which can facilitate the development of the narrow-gap thermoelectric semiconductors.

Key words: thermoelectric material, Bi2Te3-based alloy, two-band model, narrow-gap thermoelectric semiconductor

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