Appropriately designed nanocomposites allow improving the thermoelectric performance by several mechanisms, including phonon scattering, modulation doping and energy filtering, while additionally promoting better mechanical properties than those of crystalline materials. Here, a strategy for producing Bi2Te3–Cu2xTe nanocomposites based on the consolidation of heterostructured nanoparticles is described and the thermoelectric properties of the obtained materials are investigated. We first detail a two-step solution-based process to produce Bi2Te3–Cu2xTe heteronanostructures, based on the growth of Cu2xTe nanocrystals on the surface of Bi2Te3 nanowires. We characterize the structural and chemical properties of the synthesized nanostructures and of the nanocomposites produced by hot-pressing the particles at moderate temperatures. Besides, the transport properties of the nanocomposites are investigated as a function of the amount of Cu introduced. Overall, the presence of Cu decreases the material thermal conductivity through promotion of phonon scattering, modulates the charge carrier concentration through electron spillover, and increases the Seebeck coefficient through filtering of charge carriers at energy barriers. These effects result in an improvement of over 50% of the thermoelectric figure of merit of Bi2Te3.
Journal of Materials Chemistry C
This work was supported by the European Regional Development Funds and by the Spanish Ministerio de Economı´a y Competitividad through the project SEHTOP (ENE2016-77798-C4-3-R). Y. Z. and X. H., thank the China Scholarship Council for scholarship support. M. C. has received funding from the European Union’s Horizon 2020 Research and Innovation programme under the Marie Skłodowska-Curie Grant Agreement No. 665385. M. I. acknowledges financial support from IST Austria. Y. L. acknowledges funding from the European Union’s Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie grant agreement no. 754411. ICN2 acknowledges funding from Generalitat de Catalunya 2017 SGR 327 and the Spanish MINECO project ENE2017-85087-C3. ICN2 is supported by the Severo Ochoa program from the Spanish MINECO (grant no. SEV-2017-0706) and is funded by the CERCA Programme/Generalitat de Catalunya. Part of the present work has been performed in the framework of Universitat Auto`noma de Barcelona Materials Science PhD program.
Zhang Y, Liu Y, Calcabrini M, et al. Bismuth telluride-copper telluride nanocomposites from heterostructured building blocks. Journal of Materials Chemistry C. 2020;8(40):14092-14099. doi:10.1039/D0TC02182B
Zhang, Y., Liu, Y., Calcabrini, M., Xing, C., Han, X., Arbiol, J., … Cabot, A. (2020). Bismuth telluride-copper telluride nanocomposites from heterostructured building blocks. Journal of Materials Chemistry C. Royal Society of Chemistry. https://doi.org/10.1039/D0TC02182B
Zhang, Yu, Yu Liu, Mariano Calcabrini, Congcong Xing, Xu Han, Jordi Arbiol, Doris Cadavid, Maria Ibáñez, and Andreu Cabot. “Bismuth Telluride-Copper Telluride Nanocomposites from Heterostructured Building Blocks.” Journal of Materials Chemistry C. Royal Society of Chemistry, 2020. https://doi.org/10.1039/D0TC02182B.
Y. Zhang et al., “Bismuth telluride-copper telluride nanocomposites from heterostructured building blocks,” Journal of Materials Chemistry C, vol. 8, no. 40. Royal Society of Chemistry, pp. 14092–14099, 2020.
Zhang Y, Liu Y, Calcabrini M, Xing C, Han X, Arbiol J, Cadavid D, Ibáñez M, Cabot A. 2020. Bismuth telluride-copper telluride nanocomposites from heterostructured building blocks. Journal of Materials Chemistry C. 8(40), 14092–14099.
Zhang, Yu, et al. “Bismuth Telluride-Copper Telluride Nanocomposites from Heterostructured Building Blocks.” Journal of Materials Chemistry C, vol. 8, no. 40, Royal Society of Chemistry, 2020, pp. 14092–99, doi:10.1039/D0TC02182B.