Realizing the Ultralow Lattice Thermal Conductivity of Cu3SbSe4 Compound via Sulfur Alloying Effect

• Published in: Nanomaterials (Basel, Switzerland) Vol. 13; no. 19; p. 2730
• Main Authors: Zhao, Lijun, Han, Haiwei, Lu, Zhengping, Yang, Jian, Wu, Xinmeng, Ge, Bangzhi, Yu, Lihua, Shi, Zhongqi, Karami, Abdulnasser M., Dong, Songtao, Hussain, Shahid, Qiao, Guanjun, Xu, Junhua
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 08-10-2023; MDPI
• Subjects: Alloying effects; Alloying elements; Copper selenides; Crystal structure; Cu3SbSe4-based materials; Heat conductivity; Heat transfer; point defect; Point defects; S alloying; Seebeck effect; Sintering; Solid solutions; Sulfur; Thermal conductivity; Thermoelectric materials; thermoelectric properties; Thermoelectricity; Transport properties
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano13192730

Cu3SbSe4 is a potential p-type thermoelectric material, distinguished by its earth-abundant, inexpensive, innocuous, and environmentally friendly components. Nonetheless, the thermoelectric performance is poor and remains subpar. Herein, the electrical and thermal transport properties of Cu3SbSe4 were synergistically optimized by S alloying. Firstly, S alloying widened the band gap, effectively alleviating the bipolar effect. Additionally, the substitution of S in the lattice significantly increased the carrier effective mass, leading to a large Seebeck coefficient of ~730 μVK−1. Moreover, S alloying yielded point defect and Umklapp scattering to significantly depress the lattice thermal conductivity, and thus brought about an ultralow κlat ~0.50 Wm−1K−1 at 673 K in the solid solution. Consequently, multiple effects induced by S alloying enhanced the thermoelectric performance of the Cu3SbSe4-Cu3SbS4 solid solution, resulting in a maximum ZT value of ~0.72 at 673 K for the Cu3SbSe2.8S1.2 sample, which was ~44% higher than that of pristine Cu3SbSe4. This work offers direction on improving the comprehensive TE in solid solutions via elemental alloying.