1. Enhancing the Thermoelectric Performance of GeSb 4 Te 7 Compounds via Alloying Se.
- Author
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Wang, Siyu, Xing, Tong, Wei, Tian-Ran, Zhang, Jiawei, Qiu, Pengfei, Xiao, Jie, Ren, Dudi, Shi, Xun, and Chen, Lidong
- Subjects
CARRIER density ,PHASE change materials ,SEEBECK coefficient ,THERMAL conductivity ,GALLIUM antimonide ,THERMOELECTRIC materials ,ALLOYS - Abstract
Ge-Sb-Te compounds (GST), the well-known phase-change materials, are considered to be promising thermoelectric (TE) materials due to their decent thermoelectric performance. While Ge
2 Sb2 Te5 and GeSb2 Te4 have been extensively studied, the TE performance of GeSb4 Te7 has not been well explored. Reducing the excessive carrier concentration is crucial to improving TE performance for GeSb4 Te7 . In this work, we synthesize a series of Se-alloyed GeSb4 Te7 compounds and systematically investigate their structures and transport properties. Raman analysis reveals that Se alloying introduces a new vibrational mode of GeSe2 , enhancing the interatomic interaction forces within the layers and leading to the reduction of carrier concentration. Additionally, Se alloying also increases the effective mass and thus improves the Seebeck coefficient of GeSb4 Te7 . The decrease in carrier concentration reduces the carrier thermal conductivity, depressing the total thermal conductivity. Finally, a maximum zT value of 0.77 and an average zT value of 0.48 (300–750 K) have been obtained in GeSb4 Te5.5 Se1.5 . This work investigates the Raman vibration modes and the TE performance in Se-alloyed GeSb4 Te7 sheddinglight on the performance optimization of other GST materials. [ABSTRACT FROM AUTHOR]- Published
- 2023
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