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Silicon films were deposited at moderate substrate temperatures (280-500 o C) from pure silane and a silane-hydrogen mixture (10% SiH 4 , 90% H 2 ) in a hot wire CVD reactor. The morphology, structure and composition of the samples were studied with Scanning Electron Microscopy, Transmission Electron Microscopy, Transmission Electron Diffraction, X-ray diffraction, Raman-spectroscopy and Secondary Ion Mass Spectrometry. The sample deposited at 500 o C with pure silane has an amorphous structure, whereas the samples obtained from silane diluted in hydrogen have a polycrystalline structure even that grown at the lowest temperature

In this paper we present new results on doped c-Si:H thin films deposited by Hot-Wire Chemical Vapour Deposition (HWCVD) in the very low temperature range (125-275 ºC). The doped layers were obtained by the addition of diborane or phosphine in the gas phase during deposition. The incorporation of boron and phosphorus in the films and their influence on the crystalline fraction are studied by Secondary Ion Mass Spectrometry and Raman Spectroscopy respectively. Good electrical transport properties were obtained in this deposition regime, with best dark conductivities of 2.6 S/cm and 9.8 S/cm for the p-and n-doped films respectively. The effect of the hydrogen dilution and the layer thickness on the electrical properties are also studied. Some technological conclusions referred to cross contamination could be deduced from the nominally undoped samples obtained in the same chamber after p-and n-type heavily doped layers.

The possible use of poly(ethylene naphthalate) as substrate for thin silicon solar cells has been studied in this paper. The transparency of this polymer makes it a candidate to be used in both substrate and superstrate configurations. ZnO:Al has been deposited at room temperature on top of PEN. The resulting structure PEN/ZnO:Al presented good optical and electrical properties. PEN has been successfully textured (nanometer and micrometer random roughness) using Hot-Embossing Lithography. Reflector structures have been built depositing Ag and ZnO:Al on top of the stamped polymer. The deposition of these layers did not affect the final roughness of the whole. The reflector structure has been morphologically and optically analysed to verify its suitability to be used in solar cells.