Effect of substrate temperature and hydrogen dilution on thin silicon films deposited at low substrate temperatures

Amorphous and microcrystalline silicon thin films for solar cells motivated by the usage of plastic substrates have been grown by PECVD with variable dilution at T/sub S/=80/spl deg/C and variable substrate temperature T/sub S/ from 35/spl deg/C to 200/spl deg/C at r/sub H/=133. A complex characterisation including topography pictures and maps of local currents by combined AFM, crystallinity by Raman spectroscopy, conductivity, activation energy, ambipolar diffusion length by SSPG and hydrogen content by ERDA has been performed. The possible misleading results of some methods have been reported as well as the key role of hydrogen at the low temperatures facilitating the crystallite formation.