First-Principles Simulation of Hydrogen Interaction in Amorphous Silicon Nitride

Abstract

AbstractStructure and properties of amorphous hydrogented silon nitride (a- SiNx:H) are studied using density functional methods. Models of a-SiNx:H were generated using a random network algorithm. In addition we investigarted the N-H terminated surfaces of β-Si3N4.A comparison between the vibrational spectra of the surface and of the bulk models shows that within the bulk the frequency of N-H bond stretching (≈ 3150 cm-1) is lower than at the surface (≈3300 cm-1). Both spectra show an asymmetric form of the principal peak tailing towards space of hydrogen with nearby atoms. Car-Parrinello moleculat dynamic simulations at elevated temperatures show hopping of bulk hydrogen between different two bonding sites. Moreover, hydrogen acts as network transformer releasing internal stresses.