Approximate ab initio calculation of vibrational properties of hydrogenated amorphous silicon with inner voids

Abstract

We have performed an approximate ab initio calculation of vibrational properties of hydrogenated amorphous silicon (a-Si:H) using a molecular dynamics method. A 216 atom model for pure amorphous silicon (a-Si) has been employed as a starting point for our a-Si:H models with voids that were made by removing a cluster of silicon atoms out of the bulk and terminating the resulting dangling bonds with hydrogens. Our calculation shows that the presence of voids leads to localized low energy (30-50 cm^{-1}) states in the vibrational spectrum of the system. The nature and localization properties of these states are analyzed by various visualization techniques.

15 pages with 6 PS figures, to appear in PRB in December 1998

Cited by in corpus (5)

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• Low-temperature anomalous specific heat without tunneling modes: a simulation for a-Si with voids
• Realistic inversion of diffraction data for an amorphous solid: the case of amorphous silicon
• Sample dependence of the structural, vibrational, and electronic properties of a-Si:H: A density-functional-based tight-binding study
• Computer simulation of low-energy excitations in amorphous silicon with voids