Electronic structure of boron-interstitial clusters in silicon

Hybrid functional calculations within density functional theory are carried out to investigate the electronic structure of boron-interstitial clusters (BICs). A one-parameter hybrid functional is chosen is to give accurate results for the whole electronic structure (including the gap) and the elastic properties of crystalline silicon. It is shown that this approach provides dependable defect level positions in the gap. Investigation of the boron + vacancy and boron + self-interstitial centres gives a consistent description of the experimentally observed G 10 and G28 centres. The electronic structure of BICs, which may affect the activation rate of boron implantation, are reported. The one-electron level positions of isolated BnIm defects are given.