We present a study of the morphology and the thermoelectric properties of short-pulse laser-sintered (LS) nanoparticle (NP) thin films, consisting of SiGe alloy NPs or composites of Si and Ge NPs. Laser-sintering of spin-coated NP films in vacuum results in a macroporous percolating network with a typical thickness of 300 nm. The Seebeck coefficient is independent of the sintering process and typical for degenerate doping. The electrical conductivity of LS films rises with increasing temperature, best described by a power-law and influenced by two-dimensional percolation effects.Comment: 4 pages, 4 figure

Porous, highly doped semiconductors are potential candidates for thermoelectric energy conversion elements. We report on the fabrication of thin films of Ge via short-pulse laser-sintering of Ge nanoparticles (NPs) in vacuum and study the macroporous morphology of the samples by secondary electron microscopy (SEM) imaging. The temperature dependence of the electrical conductivity and the Seebeck coefficient of undoped Ge is discussed in conjunction with the formation of a defect band near the valence band. We further introduce a versatile method of doping the resulting films with a variety of common dopant elements in group-IV semiconductors by using a liquid containing the dopant atoms. This method is fully compatible with laser-direct writing and suited to fabricate small scale thermoelectric generators. The incorporation of the dopants is verified by X-ray photoelectron spectroscopy (XPS) and their electrical activation is studied by conductivity and thermopower measurements.