AB-INITIO CALCULATION OF INFRARED AND RAMAN-SPECTRA FOR HYDROGENATED AMORPHOUS-SILICON

The ab initio method with the STO-3G basis set is used to calculate th e infrared and Raman spectra of hydrogenated amorphous silicon. To rem ove the systematic deviation of the calculated frequencies due to the finite number of the basis functions and the small size of the cluster , a scaling method is used. The results are in good agreement with the experiments. The calculated results support that there are SiH, SiH2, SiH3, and (SiH2)n configurations in hydrogenated amorphous silicon. T he doublet lines are associated with the SiH3 configuration.