Berlin 2015 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 103: Transport: Poster Session
TT 103.13: Poster
Donnerstag, 19. März 2015, 15:00–18:00, Poster B
Enhanced thermoelectric figure of merit in polycrystalline carbon nanostructures — •Thomas Lehmann1,2,3, Dmitry Ryndyk1,2,3, and Gianaurelio Cuniberti1,2,3 — 1Institute for Materials Science and Max Bergmann Center of Biomaterials, TU Dresden, 01062 Dresden, Germany — 2Dresden Center for Computational Materials Science (DCCMS), TU Dresden, 01062 Dresden, Germany — 3Center for Advancing Electronics Dresden, TU Dresden, 01062 Dresden, Germany
Grain boundaries are commonly observed in carbon nanostructures, but their influence on thermal and electronic properties are still not completely understood. Using a combined approach of density functional tight-binding theory and non-equilibrium Green functions we investigate electron and phonon transport in carbon based systems. In this work, quantum transport and thermoelectric properties are summarized for graphene sheets, graphene nanoribbons and carbon nanotubes with a variety of grain boundary types in a large temperature range. Motivated by previous findings that disorder scatters phonons more effectively than electrons, a significant improvement in the thermoelectric performance for polycrystalline systems is expected. While the effect depends on the grain boundary type, we demonstrate that grain boundaries are a viable tool to greatly enhance the thermoelectric figure of merit, paving the way for the design of new thermoelectric materials.