Calculation of defects in silicon by a new tight-binding model

The structural and electronic properties of monovacancy, divacancy defects within crystalline silicon have been investigated systematically using a ne w tight-binding model with a 216-atom supercell. The formation energies and energy levels of all the defect configurations are carefully calculated. T he results show that atoms nearer to the defects naturally contribute to ga p states more, and are comparable with the experimental values.