Published online by Cambridge University Press: 16 February 2011
We have carried out a comprehensive Raman scattering study of a-S1-xCx:H alloys using three laser excitations: 458, 514, and 581 nm. The alloys studied were prepared with and without H2 dilution, had carbon concentrations, x, between 7 and 20 at %, and Taue optical gaps in the range of 1.8 ≤ Eg ≤ 2.2 eV. The results obtained explain the previous conflicting reports in the literature regarding the Si network disorder and indicate that in the Si-rich compositions, chemical clustering takes place with increasing carbon content.