ICT2014 Abstracts

Chalcogenide alloys are among the most widely studied thermoelectric materials. In particular, the Group 15 chalcogenides M₂E₃ (M = Bi, Sb; E = Te, Se) and their solid solutions are important for low temperature TE applications. It has been demonstrated that nanostructuring of these materials can lead to a significant increase in thermoelectric efficiency,¹ and this has stimulated considerable interest in developing methods for producing these materials with a high degree of nanostructuring in one or two dimensions. Among the approaches used, templated electrodeposition is one attractive avenue currently being pursued to achieve this. However, the formation of very small diameter (sub-10 nm) nanowires of elemental and compound semiconductors remains a significant challenge.

We are developing supercritical fluid electrodeposition (SCFED) as a new materials deposition technique that combines the advantages of electrodeposition (including the ability to spatially define growth and efficient reagent usage) with the unique properties of supercritical fluids (excellent pore penetration due a lack of surface tension, wide electrochemical windows and the ability to work at high temperatures). SCFED has already been successfully used to deposit a range of materials, including Ge films and 3 nm diameter Cu nanowires.²

We present a new and versatile methodology for the deposition of thermoelectric materials into extreme nanopores.

1. C. J. Vineis, A. Shakouri, A. Majumdar, M. G. Kanatzidis, Adv. Mater., 2010, 22, 3970-3980.
2. P. N. Bartlett, D. A. Cook, M. W. George, A. L. Hector, J. Ke, W. Levason, G. Reid, D. C. Smith and W. Zhang, Phys. Chem. Chem. Phys., 2014, DOI: 10.1039/c3cp54955k. The SCFED Project (www.scfed.net) is a multidisciplinary collaboration of British universities investigating the fundamental and applied aspects of supercritical fluids.