Effects of topology versus disorder on the vibrational properties of amorphous semiconductors

Publisher Website
Google Scholar
Abstract
We propose a method to isolate the effects of topology, present in the form of rings, etc., from those of disorder due to bond-angle variation. For a representative cluster based on the Polk model, we find that the effects of disorder dominate over those due to rings. The so-called LA-LO peaks in the local vibrational density of states appear only if more than six sixfold rings pass through the atom. These are suppressed if the angular disorder exceeds a critical value.