Using spectroscopic ellipsometry in the visible and near-infrared spectral range we investigate the optical properties of a growing silver film starting from predeposited gold nanoparticles. The effective pseudodielectric functions, obtained by direct inversion of the ellipsometry spectra, reveal a surface plasmon resonance for the nanoparticulate films. Upon prolonged electroless silver deposition, the resonance shifts to lower energies. The redshift is due the longer electron mean free path in larger silver structures and is analyzed by describing the optical response of the developing silver film in terms of a Lorentz line shape. The position of the oscillator, i.e., its resonance energy, is discussed in relation to the transition from isolated nanoparticles to an interconnected, eventually continuous metal film. This transition is also observed in the optical conductivity which exhibits an abrupt, stepwise increase at the same energy where the aforementioned resonance energy becomes zero. For longer deposition times, the optical spectra can be described in terms of a Drude-like free-electron metal. The development of the Drude–Lorentz parameters, i.e., the relaxation time and electron density, are compared to values for bulk silver; the latter were obtained from an optical measurement on a thick bulk silver sample. The saturation values for the relaxation time and thus the conductivity amount to approximately 40% of the bulk value, in agreement with direct current conductivity measurements on these films.

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We report on a versatile nanocolloidal route to obtain large-scale conducting metal microstructures on a silicon oxide substrate. By using microcontact printing of an aminosilane, we create functionalized regions on the silicon oxide surface onto which gold nanoparticles selectively adhere. By using an established electroless, seeded-growth process, the individual, isolated gold nanocrystals are enlarged past the percolation threshold to form conducting metal structures. Quantitative characterization of metal coverage, thickness, and roughness has been performed with scanning electron microscopy and spectroscopic ellipsometry.

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We obtained 17.9% cell efficiency on thin and large mc‐Si REC wafers using ECN's metal‐wrap‐through (MWT) concept. Optimization of several cell processing steps led to an increase of more than 2% absolute in cell efficiency. With these cells 36‐cell modules were manufactured at 100% yield in our industry scale module pilot line. The highest module efficiency obtained (as independently confirmed by JRC‐ESTI) was 17%. In this module the average cell efficiency was 17.8%; this shows a small difference between cell and module efficiency. Copyright © 2011 John Wiley & Sons, Ltd.