Bonding and diffusion in hydrogenated amorphous silicon by tight-binding molecular dynamics

The structural and bonding properties of hydrogenated amorphous silicon are investigated by tight-binding molecular dynamics. The formation of clusters and chains of hydrogen atoms is observed when quenching a hydrogenated liquid silicon sample to room temperature. In addition, the high-temperature stability of the amorphous network is investigated as a function of the hydrogen content of the sample. The amorphous silicon lattice is found to be unstable at high temperature when the hydrogen content is above 10%.