Defect states in amorphous silicon

The nature of defects in amorphous silicon is calculated by using several methods for clusters with varying size. The wave function of the dangling bond state has an approximately exponential decay with a decay length of about 0.2 nm. The correlation energy of electrons and the hyperfine structure constant with 29 Si for the dangling bond state are evaluated. The correlation energy and the g ‐values are calculated both for a weak bond and for a two‐fold coordinated defect and are compared with experiments.