RAMAN-SCATTERING MEASUREMENTS AND FRACTON INTERPRETATION OF VIBRATIONAL PROPERTIES OF AMORPHOUS-SILICON

Results of Raman scattering on a-Si:H films are presented at frequencies from 20 to 2500 cm-1. The frequency and temperature dependence of the Stokes/anti-Stokes ratio of Raman scattering intensity show the boson character of the observed broad background signal. It has been shown that the fractal model can be successfully applied to a-Si:H as well. The crossover frequency omega(co1) between phonon and fracton regimes and the fractal exponent (sigma + d - D)d/D, obtained from the frequency dependence on the Raman scattering intensity, have been determined.