Intrinsic hydrogenated nanocrystalline silicon (nc-Si:H) films were prepared on two polymer substrates, polyimide and polytetrafluoroethylene (PTFE), by hot-wire chemical vapor deposition. Polyimide has a higher service temperature (350 degrees C)) than PTFE foil substrate (260 degrees C) and a high dimensional stability, but absorbs light with wavelengths below 500 nm while PTFE substrates are capable of transmitting light of wavelengths below 200 rim. The effect of silane concentration on electrical conductivity and crystallinity were studied for films deposited at a substrate temperature of 220 degrees C. Films deposited on polyimide substrates had very similar dark conductivity and photoconductivities to those grown on glass substrates. In contrast, a silicon nitride interlayer was found necessary to obtain similar results for films deposited onto PTFE. Raman spectroscopy and X-ray diffraction showed that nanocrystalline grain size (20-65 nm) was observed for silane concentrations below 5.8% for growth on all three substrates. (c) 2008 Elsevier B.V. All rights reserved.