Regensburg 2013 – scientific programme

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DS: Fachverband Dünne Schichten

DS 24: Thermoelectric Materials

DS 24.2: Talk

Wednesday, March 13, 2013, 15:00–15:15, H32

Thermoelectric properties of laser-assisted wet-chemically doped group-IV nanoparticles — •Benedikt Stoib¹, Anton Greppmair¹, Tim Langmann¹, Nils Petermann², Hartmut Wiggers², Martin Stutzmann¹, and Martin S. Brandt¹ — ¹Walter Schottky Institut, Technische Universität München, Am Coulombwall 4, 85748 Garching — ²Institut für Verbrennung und Gasdynamik, Universität Duisburg-Essen, Lotharstraße 1, 47048 Duisburg

We present recent studies on the morphology and the thermoelectric properties of thin films of laser-sintered group-IV nanoparticles. The structure size in the macro-porous network is in the sub-µm regime and can be controlled by the laser fluence used for sintering. Doping was achieved by immersing the nanoparticle film prior to sintering in a liquid containing the dopants. Conductivity and thermopower measurements provide insight into the doping efficiency. For the doping with group-V elements we find a threshold concentration, above which the conductivity can be increased by several orders of magnitude up to 100 S/cm, using different dopant concentrations in the dopant solution. Thermopower measurements show that the laser-sintered thin films are indeed n-type after this procedure, reaching a maximum Seebeck coefficient of -270 µV/K. We present the extension of this doping method to SiGe and Si and discuss relevant materials properties affecting the efficiency of the doping process.

[1] B. Stoib et al., Phys. Stat. Solidi A, doi 10.1002/pssa.201228392 (2012)