Publication date: 8th June 2021
Thermoelectric materials can interconvert between thermal and electrical energy and thus find application in energy harvesting or temperature control technologies. However, low energy conversion efficiencies stemming from conversely intertwined material parameters strongly limit commercialization. Optimizing them requires complex materials with precise control over structural properties at the atomic-, nano-, and mesoscale. A strategy to build material with such level of structural control is through the assembly of colloidal nanocrystals. In this approach, the precisely designed colloidal nanocrystals are compacted into a bulk nanomaterial (pellet) and characterized in their thermoelectric performance. This poster will highlight different strategies to control thermoelectric performance in the bottom-up assembly of colloidal nanocrystals during the synthesis, through surface treatments, and during the nanocrystal consolidation. In the nanocrystal synthesis, we can design elemental, multinary and multicomponent nanocrystals with precise control over the nanocrystals’ shape, size, composition, and crystal phase.The native insulating hydrocarbon ligands represent a hurdle for any application that involves charge transport, as in the case of thermoelectrics. Therefore, removing or exchanging these ligands is a must but can also represent an opportunity to further tune the final solid properties. The ever-increasing library of inorganic ligands represents a valuable toolkit for material design. Nanocrystal ligands have been used to control doping, promote alloying, and introduce secondary phases in the final bulk nanomaterial. Finally, combining different types of nanocrystals represents an additional experimental knob to alter the thermoelectric performance by texturing, doping, etc.
This work was financially supported by the European Union (EU) via FP7 ERC Starting Grant 2012 (Project NANOSOLID, GA No. 306733). M.I. was supported by IST Austria, and by ETH Zurich via ETH career seed grant (SEED-18 16-2). Y.L. acknowledges funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 754411. 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.