An LCAOMOSCF calculation of the infrared spectra of SiHSi three center bonds in aSi:H

Abstract

The infrared vibrational frequencies and the disorder mode potential barriers of SiHSi bonds in hydrogenated amorphous silicon (aSi:H) are calculated. The molecular force constants and potential barriers for the SiHSi bonds are obtained from an LCAOMOSCF STO3G calculation on several configurations of the defect molecule H 3′SiHSiH 3′. The nuclear charges on the primed hydrogens (H′) have been adjusted to simulate the SiSi bonds which would be present in bulk aSi:H. The normal mode vibrational frequencies are determined using the molecular force constants and Wilson's F-G method. The results for vibrational frequencies and potential barriers are then compared with published experimental data.