Cost-Efficient Preparation and Enhanced Thermoelectric Performance of Bi0.48Sb1.52Te3 Bulk Materials with Micro- and Nanostructures

• Published in: Journal of electronic materials 2014-06, Vol.43 (6), p.1768-1774
• Main Authors: Zhu, Wan-Ting, Zhao, Wen-Yu, Zhou, Hong-Yu, Yu, Jian, Tang, Ding-Guo, Liu, Zhi-Yuan, Zhang, Qing-Jie
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conductivity phenomena in semiconductors and insulators; Cross-disciplinary physics: materials science; rheology; Electronic transport in condensed matter; Electronics and Microelectronics; Exact sciences and technology; Instrumentation; Materials Science; Nanoscale materials and structures: fabrication and characterization; Optical and Electronic Materials; Other topics in nanoscale materials and structures; Physics; Solid State Physics; Thermoelectric and thermomagnetic effects
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-013-2857-8

A cost-efficient method has been developed based on the combination of hydrothermal exfoliation and spark plasma sintering (SPS) to fabricate Bi 0.48 Sb 1.52 Te 3 bulk material with multiscale microstructures composed of micro- and nanosized microstructures. The thermoelectric (TE) transport properties of the bulk material with multiscale microstructures were measured along the directions parallel (||) and perpendicular (⊥) to the SPS pressing direction. It is confirmed that the anisotropy of the electrical conductivity ( σ ) and thermal conductivity ( κ ) was decreased by the transformation of the microstructure from a single microscale structure to multiscale microstructures. As compared with Bi 0.48 Sb 1.52 Te 3 bulk material with single microscale microstructures, the κ value of the Bi 0.48 Sb 1.52 Te 3 bulk material with multiscale microstructures was significantly reduced, the σ value was slightly decreased, while the α value was slightly increased. Thus, a maximum ZT value of 1.1 was achieved at 350 K along the direction perpendicular to the pressing direction, increased by 20%. The enhanced ZT value was mainly attributed to the significant decrease in κ induced by the multiscale microstructures. This work offers a new approach to improve TE performance by multiscale microstructural engineering.