Origin of inhomogeneity in spark plasma sintered bismuth antimony telluride thermoelectric nanocomposites

• Published in: Nano research Vol. 13; no. 5
• Main Authors: Shi, Enzheng, Cui, Shuang, Kempf, Nicholas, Xing, Qingfeng, Chasapis, Thomas, Zhu, Huazhang, Li, Zhe, Bahk, Je-Hyeong, Snyder, G. Jeffrey, Zhang, Yanliang, Chen, Renkun, Wu, Yue
• Format: Journal Article
• Language: English
• Published: United States Springer 18.12.2019
• Subjects: bismuth antimony telluride; inhomogeneity; MATERIALS SCIENCE; NANOSCIENCE AND NANOTECHNOLOGY; solution synthesis; thermoelectrics
• ISSN: 1998-0124; 1998-0000

Anisotropy and inhomogeneity are ubiquitous in spark plasma sintered thermoelectric devices. However, the origin of inhomogeneity in thermoelectric nanocomposites has rarely been investigated so far. Herein, we systematically study the impact of inhomogeneity in spark plasma sintered bismuth antimony telluride (BiSbTe) thermoelectric nanocomposites fabricated from solution-synthesized nanoplates. The figure of merit can reach 1.18, which, however, can be overestimated to 1.88 without considering the inhomogeneity. Our study reveals that the inhomogeneity in thermoelectric properties is attributed to the non-uniformity of porosity, textures and elemental distribution from electron backscatter diffraction and energy-dispersive spectroscopy characterizations. This finding suggests that the optimization of bulk material homogeneity should also be actively pursued in any future thermoelectric material research.