Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published April 26, 2011 | Supplemental Material
Journal Article Open

Surfactant-Free Synthesis of Bi_(2)Te_(3)-Te Micro-Nano Heterostructure with Enhanced Thermoelectric Figure of Merit

Abstract

An ideal thermoelectric material would be a semiconductor with high electrical conductivity and relatively low thermal conductivity: an "electron crystal, phonon glass". Introducing nanoscale heterostructures into the bulk TE matrix is one way of achieving this intuitively anomalous electron/phonon transport behavior. The heterostructured interfaces are expected to play a significant role in phonon scattering to reduce thermal conductivity and in the energy-dependent scattering of electrical carriers to improve the Seebeck coefficient. A nanoparticle building block assembly approach is plausible to fabricate three-dimensional heterostructured materials on a bulk commercial scale. However, a key problem in applying this strategy is the possible negative impact on TE performance of organic residue from the nanoparticle capping ligands. Herein, we report a wet chemical, surfactant-free, low-temperature, and easily up-scalable strategy for the synthesis of nanoscale heterophase Bi_(2)Te_(3)-Te via a galvanic replacement reaction. The micro-nano heterostructured material is fabricated bottom-up, by mixing the heterophase with commercial Bi_(2)Te_3. This unique structure shows an enhanced zT value of ~0.4 at room temperature. This heterostructure has one of the highest figures of merit among bismuth telluride systems yet achieved by a wet chemical bottom-up assembly. In addition, it shows a 40% enhancement of the figure of merit over our lab-made material without nanoscale heterostructures. This enhancement is mainly due to the decrease in the thermal conductivity while maintaining the power factor. Overall, this cost-efficient and room temperature synthesis methodology provides the potential for further improvement and large-scale thermoelectric applications.

Additional Information

© 2011 American Chemical Society. Received for review January 25, 2011, and accepted March 8, 2011; published online March 8, 2011. The authors sincerely thank A. Palmqvist, C. Levi, G. Zeng, R. Leckie, D. Cederkrantz, K. Fields, B. Curtin, and A. Ivanovskaya for helpful discussions and assistance with instrument use. This work was supported in part by the Center for Energy Efficient Materials (CEEM), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Basic Energy Sciences under Award Number DE-SC0001009, and in part by the National Science Foundation under Grant No. DMR-0805148. The MRL Central Facilities are supported by the MRSEC Program of the NSF under Award No. DMR05-20415, a member of the NSF-funded Materials Research Facilities Network (www.mrfn.org).

Attached Files

Supplemental Material - nn2002294_si_001.pdf

Files

nn2002294_si_001.pdf
Files (3.5 MB)
Name Size Download all
md5:5840f68febd8e371813f4fd71c153d41
3.5 MB Preview Download

Additional details

Created:
August 22, 2023
Modified:
October 23, 2023