Calculation of Core Structure and Core Energy of Screw and 60° Dislocations in Si: Tight-Binding Method

A tight-binding type electronic theory is used to calculate the core structure and core energy of both screw and 60° dislocations in Si. The repulsive interaction energies at short distances are simulated by a Born-Mayer potential. It is shown that the glide-set dissociated dislocations are more stable than the corresponding shuffle-set perfect dislocation. The calculated core structures and core energies are compared with those of previous theoretical calculations as well as with available experimental results.