Vacancies which formed in amorphous material were studied by using the tight-binding molecular dynamics method. Properties such as the electronic density of states and the volume change of a single vacancy at various sites were obtained. The bond-angle deviation and the average valence charge of atoms next to a vacancy were analyzed and were found to be closely related. Although high densities of vacancies could be annihilated at room temperature, no migration of vacancies was observed in the simulations at up to 450K. The divacancy in amorphous material was found to behave similarly to a single vacancy of other types. There were many similarities between the vacancies in amorphous and crystalline material, but there were also significant differences in some of their properties.

Vacancies in amorphous silicon E.Kim, Y.H.Lee, C.Chen, T.Pang: Physical Review B, 1999, 59[4], 2713-21