Enhanced thermoelectric performance of Bi2Se3/TiO2 composite

• Published in: Rare metals Vol. 39; no. 8; pp. 887 - 894
• Main Authors: Yang, Yu-Xi, Wu, Ye-Hao, Zhang, Qi, Cao, Gao-Shao, Zhu, Tie-Jun, Zhao, Xin-Bing
• Format: Journal Article
• Language: English
• Published: Beijing Nonferrous Metals Society of China 01.08.2020; Springer Nature B.V
• Subjects: Biomaterials; Carrier density; Chemistry and Materials Science; Composite materials; Energy; Figure of merit; Hot pressing; Materials Engineering; Materials Science; Metallic Materials; N-type semiconductors; Nanoscale Science and Technology; Physical Chemistry; Power factor; Refrigeration; Room temperature; Thermal conductivity; Thermoelectric materials; Titanium dioxide; Thermoelectric materials; Te,Se; TiO; Composite; Bi
• ISSN: 1001-0521; 1867-7185
• DOI: 10.1007/s12598-020-01414-4

Bi 2 (Te,Se) 3 alloys are conventional commercial thermoelectric materials for solid-state refrigeration around room temperature. In recent years, much attention has been paid to various advanced thermoelectric composite materials due to the unique thermoelectric properties. In this work, Bi 2 Se 3 /TiO 2 composites were prepared by hot pressing the plate-like Bi 2 Se 3 powders coated in situ with hydrolyzed hytetabutyl- n -butyl titanate (TNBT), and therefore numerous TiO 2 in micrometer size could be formed on the interface of Bi 2 Se 3 grains. The carrier concentration in Bi 2 Se 3 matrix is optimized subject to the addition of n-type semiconductor TiO 2 , contributing to a significant improved power factor. In the meantime, the lattice thermal conductivity is also suppressed due to the enhanced phonon scattering at Bi 2 Se 3 /TiO 2 interface and amorphous TiO 2 particles. As a consequence, a peak figure of merit ( zT ) of 0.41 is obtained at 525 K in Bi 2 Se 3 /15 mol% TiO 2 composites, nearly 50% augment over the pristine Bi 2 Se 3 binary compound.