Thermoelectric properties of solution-synthesized n-type Bi2Te3 nanocomposites modulated by Se： An experimental and theoretical study

• Published in: Nano research 2016-01, Vol.9 (1), p.117-127
• Main Authors: Fang, Haiyu, Bahk, Je-Hyeong, Feng, Tianli, Cheng, Zhe, Mohammed, Amr M. S., Wang, Xinwei, Ruan, Xiulin, Shakouri, Ali, Wu, Yue
• Format: Article
• Language: English
• Subjects: Atomic/Molecular Structure and Spectra; Bi2Te3; Biomedicine; Biotechnology; Bismuth tellurides; Carrier density; Chemistry and Materials Science; Condensed Matter Physics; Figure of merit; Materials Science; Nanocomposites; Nanotechnology; Nanowires; Pellets; Power factor; Research Article; Synthesis; Thermal conductivity; Thermoelectricity; Transport; 材料合成; 热电性能; 硒溶液; 纳米复合材料; 试验; 调制; 载流子浓度
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-015-0892-x

We report the investigation of the thermoelectric properties of large-scale solution-synthesized Bi2Te3 nanocomposites prepared from nanowires hot- pressed into bulk pellets. A third element, Se, is introduced to tune the carrier concentration of the nanocomposites. Due to the Se doping, the thermoelectric figure of merit （ZT） of the nanocomposites is significantly enhanced due to the increased power factor and reduced thermal conductivity. We also find that thermal transport in our hot-pressed pellets is anisotropic, which results in different thermal conductivities along the in-plane and cross-plane directions. Theoretical calculations for both electronic and thermal transport are carried out to establish fundamental understanding of the material system and provide directions for further ZT optimization with adjustments to carrier concentration and mobility.